OPINION
EASTAUGH, Justice.I. INTRODUCTION
Matilda W., a Caucasian living in Bethel, petitioned to adopt three sibling Native children. The superior court granted her petitions over the objections of the Native Village of Kasigluk and a Native couple who were interested in adopting the children. The Indian Child Welfare Act1 (ICWA) establishes preferences for placing an Indian child within the child’s extended family, with other members of the child’s tribe, or with other Indian families.2 The prevailing social *1020and cultural standards of the Indian community apply in meeting the preference requirements.3 A court may deviate from these preferred placements only upon a showing of “good cause.”4
Do the prevailing social and cultural standards also govern the good cause determination? We hold that they do not, but that they remain relevant if the good cause inquiry raises questions about the suitability of a statutorily preferred placement. They may also inform, but need not control, any determination of whether a child’s special needs or other circumstances constitute good cause to deviate from the preferences.
Because the superior court’s good cause findings in this case are supported by the evidence and do not implicate the suitability of a preferred placement, we affirm its determination that there is good cause to deviate from the preferences. We therefore affirm the decrees granting Matilda W.’s adoption petitions.
II. FACTS AND PROCEEDINGS
Sara J., Joel J., and Morris J. are the biological children of Isabel B. and Roger J., who were members of the Native Village of Hooper Bay and the Native Village of Kasi-gluk, respectively.5 The oldest child was born in 1994; the youngest was born in 1999. The parental rights of Isabel and Roger were terminated in January 2003.
Sara and Morris first entered state custody in 1997 and were placed with a relative in Kasigluk for a year and a half. They were briefly returned to their parents, but were removed soon after Joel’s birth. Joel’s medical problems required that he be close to a hospital, and he was placed in a Bethel home, and then with Matilda W., an unrelated Caucasian woman living in Bethel. Sara and Morris later rejoined Joel when they were placed with Matilda after the Alaska Office of Children’s Services (OCS), formerly known as the Alaska Division of Family and Youth Services, received reports of harm while they were placed with a relative in Bethel.
OCS continued to seek a workable relative placement for the J. children, next placing them with Jake and Ruby B., the children’s maternal uncle and aunt. After Joel was hospitalized, OCS removed him from that placement, placing him again with Matilda in January 2002. Sara and Morris joined him there a month later.
Frank and Tonya B., another maternal uncle and aunt, became interested in having the J. children placed with them, and sought a foster licensing in the summer of 2003. Matilda petitioned to adopt the three J. children in July 2003.
The Native Village of Kasigluk, as the tribe with the most significant contacts, intervened pursuant to Alaska Adoption Rule 12(a) and opposed Matilda’s three adoption petitions. The superior court conducted a six-day trial on whether to grant Matilda’s petitions. The superior court found good reason to deviate from ICWA placement preferences and granted Matilda’s petitions. The superior court found that the children have special educational and behavioral needs that are best met by Matilda in Bethel, that the children’s ability to attach would be irrevocably destroyed and severe damage would result if they were removed from Matilda’s care, and that it was in the children’s best interests to grant Matilda’s adoption petitions. It also found that Matilda could adequately meet the children’s cultural needs in Bethel and that the state had made active efforts to place the children in a long-term preferred placement. The superior court issued decrees of adoption for each child.
The Native Village of Kasigluk and Frank and Tonya B. appeal, arguing that the good cause determination under ICWA must be governed by the prevailing social and cultural standards of the Indian community and that the superior court’s findings were unsupported by the evidence. The appellants filed a joint brief. We refer to them collectively as *1021the “tribe.” The state and Matilda W. are appellees.
III. DISCUSSION
A. Standard of Review
We review a finding of good cause to deviate from ICWA preferences for abuse of discretion.6 It would be an abuse of discretion for a superior court to consider improper factors or improperly weigh certain factors in making its determination.7 Determining whether the superior court’s findings comport with the requirements of ICWA raises a question of law that we decide de novo.8 We review findings of fact for clear error.9 A factual finding is clearly erroneous when we are “left with a definite and firm conviction that the trial court has made a mistake.”10
B. The Prevailing Social and Cultural Standards of the Relevant Indian Community Have Only Limited Application in Determining Whether Good Cause Exists To Depart from ICWA’s Adoptive Preferences.
Congress enacted the Indian Child Welfare Act out of concern over the unwarranted break-up of Indian families caused by removal of children by state authorities and the placement of “an alarmingly high percentage of such children” with non-Indian foster and adoptive placements.11 In an effort to reverse this trend, ICWA specifies preferred adoptive placements for Indian children.12 Thus, 25 U.S.C. § 1915(a) provides:
In any adoptive placement of an Indian child under State law, a preference shall be given, in the absence of good cause to the contrary, to a placement with (1) a member of the child’s extended family; (2) other members of the Indian child’s tribe; or (3) other Indian families.
Furthermore, Congress intended in enacting ICWA that “white, middle-class standards” not be used in determining whether preferred placements are suitable.13 Instead, § 1915(d) provides:
The standards to be applied in meeting the preference requirements of this section shall be the prevailing social and cultural standards of the Indian community in which the parent or extended family resides or with which the parent or extended family members maintain social and cultural ties.
The three preferred placements listed in § 1915(a) comprehensively rank the different possible family and Indian placements. Only for “good cause” may a state deviate from the three preferred placements, i.e., approve a placement with someone who is neither extended family nor Indian.14 The “prevailing social and cultural standards of the Indian community” described in § 1915(d) unquestionably apply to disputes about the suitability of the preferred placements listed in § 1915(a). We will sometimes refer to these as “community,” “prevailing,” or “social and cultural” standards.
But these standards do not override or change the preference requirements of *1022§ 1915. Under § 1915(d) the prevailing standards are to be used “in meeting the preference requirements,” not to override them. This means that within a preference tier the prevailing standards are to be used in selecting a placement. But as the statute is structured, it appears that social and cultural standards taken alone cannot provide for a different order of preference. In other words, community standards notwithstanding, an extended family member entitled to first-tier preference under § 1915(a) will occupy a higher tier of preference than a no-nextended family member of the child’s tribe entitled to a second-tier of preference under the same subsection. Of course community standards may be reflected in a tribal resolution setting a different order of preference under § 1915(d) and if this is done the new order of preference is legally established. Furthermore, the standards are to be used in determining the suitability or unsuitability of a prospective placement. They may, for example, support a conclusion that a higher-tier potential custodian is unsuitable, thus clearing the way for a lower-tier custodian.
The tribe’s main contention on appeal is that these standards also apply to any dispute under § 1915(a) about whether good cause exists to deviate from those placement preferences. The tribe argues that the superior court erred by failing to consider the prevailing social and cultural standards of the Village of Kasigluk when it decided whether there was good cause to grant Matilda’s petitions for adoption. In considering whether these standards apply to the good cause determination, we look to the statutory language, legislative history,15 the interpretátion given the statute by the Bureau of Indian Affairs (BIA), and relevant case law.16
Because we read most of these sources, particularly the text of the statute and the BIA’s interpretation, to indicate that the prevailing social and cultural standards of the Indian community are not generally applicable to the good cause determination, we ultimately disagree with the tribe. Nonetheless, because ICWA’s purpose and the BIA’s interpretation make the prevailing social and cultural standards relevant to the good cause determination insofar as this determination may implicate the suitability of a statutorily preferred placement candidate, many of the tribe’s concerns are minimized. Furthermore, the superior court may refer to the prevailing social and cultural standards of the Indian community in determining whether a child’s special needs or other circumstances are sufficient to establish good cause to deviate from § 1915(a)’s placement preferences.
The plain language of § 1915 suggests that the prevailing social and cultural standards do not apply to the good cause determination. Subsection 1915(d) dictates that the prevailing Indian standards are “to be applied in meeting the preference requirements of this section.”17 Subsection 1915(a) mandates that these preferences be applied “in the absence of good cause to the contrary.”18
The tribe, in arguing that ICWA’s plain language requires application of the standards to the good cause determination, contends that “[t]he ‘preference requirements’ of § 1915 of the ICWA can be ‘met’ either by giving an adoptive preference to a priority *1023placement, or by showing that there is ‘good cause to the contrary.’ ” (Emphasis in original.) The tribe argues that the phrase “meeting the preference requirements” plainly includes the good cause inquiry and that we should not create an “exemption” from the prevailing social and cultural standards of the Indian community for the good cause determination.
But we cannot agree with the tribe and the concurring opinion that the phrase “meeting the preference requirements” in § 1915(d) plainly includes § 1915(a)’s good cause inquiry.19 In our view, a court applies the “preference requirements” by determining the suitability of potential preferred placements using the prevailing social and cultural standards of the Indian community.
Although they are part of a common statutory scheme, inquiries into suitable preferred placements are separate from inquiries into good cause. It is not plain from the language of the statute that standards applicable to the issue of the suitability of preferred placements must necessarily also' apply to the issue of good cause. Rather, accepted principles of statutory interpretation suggest that the opposite is true.
Congress specified in § 1915(d) that the prevailing social and cultural standards are the standards “to be applied in meeting the preference requirements,” but did not specify that these standards be applied to the good cause inquiry. Its failure to do so suggests that it did not intend the standards to apply to the good cause inquiry. Had Congress intended the states to apply the prevailing Indian standards when determining whether there is good cause to deviate from the preferences, we think it would have expressed itself more clearly.20 For example, § 1915(d) could have stated generally that the prevailing Indian standards apply to disputes under § 1915(a). Or it could have specified that they apply “in determining whether there is good cause.” Instead, by dealing with nonNative placements in the good cause clause, Congress appears to have intended that questions of the need for non-Native placements be conceptually separate from disputes about whether a preferred placement is suitable.21
The tribe also argues that in interpreting statutes that protect the rights of Native Americans, this court must resolve any ambiguity in favor of Native Americans.22 According to the BIA, Congress left the primary responsibility for interpreting ICWA to the courts deciding Indian child custody cases.23 We have recognized that other authorities interpreting the same provisions may also be useful.24 In dealing with statutes protecting the rights of Native Americans, “the standard principles of statutory construction do not have their usual force.”25 But this principle is not a license to disregard the clearly expressed intent of *1024Congress, nor does it “permit reliance on ambiguities that do not exist.”26 United States Supreme Court opinions interpreting statutes protecting the rights of Native Americans have not completely disregarded traditional precepts of statutory interpretation.27
A fair appraisal of §§ 1915(a) and (d) demonstrates a congressional intent to apply the prevailing social and cultural standards of the Indian community to determinations of suitability of potential preferred placements, but not to determinations of good cause to deviate from the preferences. ICWA’s context points to the same conclusion.
The context of ICWA’s enactment suggests that the prevailing social and cultural standards of the Indian community do not apply to the good cause determination. The House Report’s analysis of section 5, later codified as § 1915(d), stated that “[a]ll too often, State public and private agencies, in determining whether or not an Indian family is fit for foster care or adoptive placement of an Indian child, apply a white, middle-class standard which, in many cases, forecloses placement with the Indian family.”28 The House Report also stated that “[d]is-eriminatory standards have made it virtually impossible for most Indian couples to qualify as foster or adoptive parents, since they are based on middle-class values.”29 Congress was clearly worried about the application of white, middle-class values to suitability determinations. Because the good cause inquiry is distinct from the suitability inquiry for preferred placement candidates, it falls outside the purview of Congress’s intent for the prevailing social and cultural standards of the Indian community.
The tribe argues that the same context supports its proposed interpretation. Congress found that in placing Indian children, state courts and agencies have “failed to recognize the essential tribal relations of Indian people and the social and cultural standards prevailing in Indian communities and families.”30 Congress enacted ICWA in large measure to protect “the best interests of Indian children and to promote the stability and security of Indian tribes and families by the establishment of minimum Federal standards for ... placement ... which will reflect the unique values of Indian culture.” 31 The use of the prevailing social and cultural standards of the Indian community to determine the suitability of preferred placements furthers this end and addresses the specific concern voiced by Congress. We are not persuaded that applying the prevailing social and cultural standards of the Indian community to the good cause determination is necessary to advance ICWA’s purposes.
Subsection 1915(a) “establish[es] a Federal policy that, where possible, an Indian child should remain in the Indian community, but is not to be read as precluding the placement of an Indian child with a non-Indian family.” 32 But in cases contested by Indian communities, this could be precisely the effect of applying the communities’ prevailing social and cultural standards to the good cause *1025determination.33 There was evidence here that Yup’ik standards dictate that Yup’ik children should invariably be raised by Yup’ik people. Applying the prevailing social and cultural standards to the good cause determination would effectively nullify the good cause exception in any case in which a tribe intervened under Alaska Adoption Rule 12(a) and offered equivalent evidence.34 Such a result would be contrary to accepted precepts of statutory interpretation.
The tribe notes that almost every ICWA case involves a determination of good cause. This suggests to the tribe that applying nonNative standards to the good cause determination would create a loophole, eviscerating the protections of ICWA. The tribe’s fear is misplaced. First, as outlined below, in determining whether good cause exists, “white, middle-class” standards may not be applied to reassess the suitability of a preferred placement. Second, under Alaska law the burden of showing good cause is on the party proposing placement outside the statutory preferences.35 The BIA Guidelines for State Courts note that this allocation of the burden of proof is necessary “[s]inee Congress has established a clear preference for placements within the tribal culture.”36 (The BIA issued the Guidelines to provide nonbinding guidance to state courts interpreting ICWA.37) We are satisfied that these protections, together with the sound judgment of Alaska’s trial courts, are sufficient to preserve ICWA’s protections for Indian children and communities.
The tribe suggests that our cases are not inconsistent with applying the prevailing social and cultural standards of the Indian community to the good cause determination, but only reflect the lack of evidence of those standards. Thus, it contends that applying these standards is required in this case where, for the first time, the “tribal-standards mandate of § 1915(d) [is] directly at issue.” The tribe’s approach is problematic in several respects. First, the tribe offers no criterion by which to measure whether sufficient evidence of the prevailing social and cultural standards of the Indian community has been presented to determine good cause based on those standards. Second, it would create unnecessary uncertainty in litigation, as the state and potential non-Native placements could not be certain of the standard by which-they had to prove good cause until the trial was well underway. This would prolong litigation in cases which require expeditious resolution.38
The tribe also argues that cases from other jurisdictions support its contention that the prevailing social and cultural standards of the Indian community apply to the good cause determination. In Matter of Baby Boy Doe,39 the Idaho Supreme Court addressed this question. After quoting the BIA Guidelines regarding the good cause inquiry, the court stated that
[i]n determining whether “good cause” existed, the trial court rejected the arguments by the adoptive parents’ counsel that the child is old enough to request a preference; the child has extraordinary *1026physical needs mitigating against the preferences; and that the proposed Indian placement (with the maternal aunt and uncle) is unsuitable. The trial court demonstrated knowledge of applicable legal standards in rejecting the adoptive parents’ argument that negative social and economic conditions on the reservation constitute good cause. The trial court correctly held that ICWA requires the court to apply the prevailing social and cultural standards of the Indian community.[40]
In Baby Boy Doe, the non-Native adoptive parents mistakenly argued that negative social and economic conditions on the reservation constituted good cause for departing from the preferences.41 But these conditions would be relevant, if at all, to the suitability of potential Native relative placements, and as such had to be viewed in light of the prevailing social and cultural standards of the Indian community. The court’s language does not suggest that the child’s ability to “request a preference” or the existence of “extraordinary physical needs” is governed by the prevailing social and cultural standards of the Indian community.42
The Baby Boy Doe court suggested that whether the psychological need for permanence could be satisfied by a relative placement should be analyzed in light of an Indian standard.43 But the court ultimately affirmed the finding of good cause based on the biological mother’s preference, the certainty of emotional trauma if the child was removed from the adoptive parents, and the likelihood of emotional trauma if the child encountered the father while living on the reservation.44 In concluding that these considerations together constituted good cause under “the applicable legal standards,” it did not discuss them with reference to the prevailing social and cultural standards of the Indian community.45 The court instead approved of applying the prevailing social and cultural standards of the Indian community primarily to the determination of suitability.46
Similarly, In re Jullian B. reversed a finding of good cause because the trial court failed to consider several factors in light of the prevailing social and cultural standards of the Indian community.47 The social worker in that case was concerned about the potential placement’s “age, his inability to suggest a person who could care for the minor if he became incapacitated, his prior conviction for vehicular manslaughter of a child when he was driving under the influence, his failure to rehabilitate for many years ... [and] his health and his lack of support system_”48 None of these concerns implicated special needs of the child. Instead, each of these factors was relevant to the suitability of the potential Native relative placement, and thus had to be considered in light of the prevailing social and cultural standards of the Indian community.49 The court ultimately reversed on other grounds,50 but never suggested that the prevailing social and cultural standards of the Indian community apply to anything determining the suitability of preferred placements.
These cases recognize that the prevailing social and cultural standards apply to determinations of the suitability of preferred placements even if the suitability determinations arise in the context of the good cause inquiry. We do not read these cases as *1027requiring that the prevailing social and cultural standards of the Indian community apply to all aspects of the good cause inquiry.
Our conclusion that the prevailing social and cultural standards of the Indian community do not generally apply to the good cause determination is supported by the ■ BIA Guidelines, which suggest three factors to consider in determining good cause:
(i) The request of the biological parents or the child when the child is of sufficient age.
(ii) The extraordinary physical or emotional needs of the child as established by testimony of a qualified expert witness.
(iii) The unavailability of suitable families for placement after a diligent search has been completed for families meeting the preference criteria.[51]
As the Guidelines observe, the legislative history indicates that the “term ‘good cause’ was designed to provide state courts with flexibility in determining the disposition of a placement proceeding involving an Indian child.”52 This flexibility is not a license to impose non-Native standards when courts consider the suitability of statutorily preferred placement candidates. Rather, it is an authorization to take the child’s special needs into account when determining whether good cause exists to place the child outside the statutory preferences despite the existence of an otherwise suitable home within the preferences.
Applying “white, middle-class” standards to the suitability inquiry as an aspect of the good cause determination could effectively read the preference requirements and the prevailing social and cultural standards of the Indian community out of the statute. This would occur if courts, while determining whether there is good cause for deviating from the statutorily preferred placements, could apply white, middle-class standards to examine or reexamine the suitability of a Native or relative placement deemed suitable under prevailing Indian social and cultural standards. This is the very problem ICWA was enacted to eliminate. Our holding today respects the purposes of ICWA by preventing non-Native standards from being used to decide that a preferred placement is not suitable.
The qualifications required of expert witnesses in our ICWA cases reinforce this conclusion. In some parental rights termination cases, experts with specialized knowledge of the Native culture are needed because social workers without expertise are unable to distinguish between the prevailing standards of the Indian community and actual abuse and neglect.53 But so long as issues of cultural bias are not implicated, experts need not have training in the cultural standards of the Indian community.54 These rules reflect an implied judgment that while the suitability of a Native household must be' viewed in light of the prevailing social and cultural standards of the Indian community, courts are not compelled to analyze a child’s special needs according to those standards. Such needs would demonstrate good cause if, as the superior court found here, adequate facilities to address them were not available to the preferred placement but were available to the non-preferred placement.55
*1028In determining whether a child’s special needs rise to the level that constitute good cause to deviate from the preferences, the superior court may consider the prevailing social and cultural standards of the Indian community. Courts should be sensitive to any differences in the circumstances that allow children to flourish in Native and nonNative communities. But courts need not ultimately apply the prevailing social and cultural standards of the Indian community in determining whether the resources available to an otherwise-suitable preferred placement are adequate to address the child’s special needs.
The concurring opinion contends that the prevailing social and cultural standards of the Indian community directly apply to the good cause determination. This contention is grounded on a perception of the role of the placement preferences and the good cause determination fundamentally different from our own. The concurring opinion suggests that the good cause determination is a device for choosing between non-preferred placements and suitable preferred placements.56 If this were indeed the role of the good cause inquiry, we would agree that the prevailing social and cultural standards of the Indian community must govern.
But although it is correct that the word “preference” generally connotes a choice between two options,57 we read ICWA’s structure and purpose to preclude choosing between preferred and non-preferred placements if the preferred placement is “suitable,” as measured by the prevailing social and cultural standards of the Indian community. The existence of a suitable preferred placement precludes any consideration of a non-preferred placement unless good cause exists, for example, because another preference has been expressed by the child or the child’s biological parents, or because the child has special needs that cannot be met by an otherwise-suitable preferred placement.
The concurrence also contends that the court’s interpretation of § 1915 creates an “unrealistic dichotomy” between placement decisions and good cause determinations.58 It characterizes the suitability determination required for a preferred placement and the “special needs” assessment necessaiy for a good cause determination as “flip sides of the same coin.”59 But that is not how the words of the statute treat them. The statute expressly envisions “good cause” as an exception to the general rule of preferred placements. As noted above, the proponent of placing a child in a non-preferred placement bears the burden of demonstrating that the child’s special needs require that placement. The concurrence is doubtless correct in saying that any placement decision involves examining more than “a potential placement’s abstract ability to care for a hypothetical child.”60 But a good cause determination is nonetheless legally and analytically distinct from a placement decision. It requires extenuating circumstances beyond the typical considerations at issue in a placement decision.
In holding that the prevailing social and cultural standards of the Indian community apply to the good cause determination only when it implicates a preferred placement’s suitability, we recognize our disagreement with a decision of the Minnesota Supreme Court. In Matter of Custody of S.E.G., that court rejected a trial court’s finding that the need for permanence was an extraordinary emotional need and that adoption was the only way to meet that need.61 On appeal, the court held that evidence of a special need for permanence must be presented by qualified experts with knowledge of the Indian community, suggesting that “permanency is defined differently in Native American cultures.” 62 The court thus seemingly integrated the prevailing social and cultural stan*1029dards of the Indian community of § 1915(d) into the § 1915(a) good cause analysis while leaving open the possibility that the location of necessary treatment services would not fall under § 1915(d)’s purview.63 Nevertheless, we believe that the words of the statute, the context of the legislation, and the BIA Guidelines support our holding.
C. Substantial Evidence Supported the Superior Court’s Findings.
The tribe argues that the superior court’s findings were not supported by substantial evidence. Many of its arguments hinge on its contention, rejected above, that the superior court erred by not applying the prevailing social and cultural standards of the Indian community. The superior court was not required to apply those standards, but we still review the tribe’s factual contentions.
1. The superior court did not err in finding that harm to the children from living outside the village was outweighed by the potential harm from being separated from Matilda.
The tribe asserts that the superior court erred in finding that the damage to the J. children from being separated from Matilda would outweigh the damage that severance from their Yup’ik heritage would cause the children. The tribe asserts that “the Yup’ik standard gives less weight to the short-term disruption that a removal from [Matilda’s] home might cause.” The tribe believes that this disruption is outweighed by the lack of a “compass and foundation in life” that would result from the children being separated “from the life blood of their culture,” and that “the children will melt ‘like butter’ into the supportive environment of [their] home and village community.” This is essentially an argument that the superior court should have conducted a “best interests of the child” analysis using the prevailing Yup’ik standards. But the children’s special needs do not implicate the determination of suitability for a preferred placement and need not be analyzed using the prevailing social and cultural standards of the Indian community. The evidence suggests that removing the children from Bethel and Matilda would cause them special harm.64
Morris attends counseling in Bethel. His counselor, Jennifer Cashion, testified that he would likely suffer some regressive behavior if he had to change clinicians before a new therapeutic relationship could be established. Dr. Maclan, a clinical psychologist acquainted with the children and their needs, testified that Monis needs structure. Cashion testified that Morris exhibits symptoms of post-traumatic stress syndrome, and Matilda and another witness testified to the devastating impact another move would have on him. Sara has been diagnosed with an unspecified adjustment disorder and meets criteria designated for emotionally disturbed children. Sara’s former counselor expressed both short- and long-term concerns for Sara if she is moved. We also note that Matilda testified that Morris told her that he wanted to be adopted by her.
There was evidence of the dangers inherent in raising Indian children in non-Native households. Dr. Roll testified that Native children raised in non-Native homes are at risk of erosion of language skills, identity, and cultural confusion, identity diffusion, and identification with the aggressor. But Dr. Maclan testified that these concerns can be mitigated in this case by taking advantage of opportunities in Bethel to encourage a positive view of the children’s culture through contact with the Yup’ik culture. As outlined below, Matilda has demonstrated a willing*1030ness and ability to expose the children to Yup’ik culture.
In light of the evidence discussed above, we cannot say that the superior court erred in finding that the damage that woúld be caused by separation from Matilda implicated special emotional needs, and together with the children’s behavioral and educational needs, constituted good cause to deviate from the preferences. Nor does the tribe argue that Matilda is ineligible to adopt the children under state law.
2. The superior court did not err in finding that the children’s special needs could be met in Bethel, but not in the village.
The tribe also disputes the superior court’s finding that the children’s behavioral and educational needs could be met better in Bethel by Matilda than in Chevak with Frank and Tonya B.
Expert testimony established that the J. children have special needs. Sara has been diagnosed with an unspecified adjustment disorder and falls under criteria designated for emotionally disturbed children. Morris has been diagnosed with static encephalopathy and fetal alcohol spectrum disorder (FASD). Joel has been diagnosed with static encephalopathy, is hyperactive, exhibits poor short-term memory, and suffers from developmental delays and behavioral problems. Both Morris and Joel qualify for special education. Morris was in counseling at the time of trial.
Jackson S., the tribe’s expert witness on raising children with special needs in the village setting, testified that he relied upon his twenty-eight-year-old and sixteen-year-old sons, his grandchildren, his extended family, and various services and workshops outside his village to help raise his adopted daughter, diagnosed with fetal alcohol syndrome (FAS). Tonya B.’s familial support network is not so extensive, consisting of Frank B.’s three siblings and her niece. She also stated that she would depend on her fourteen-year-old daughter for help. Although Frank testified that there are “helpers and providers” in the village for children with FAS, he had only superficial familiarity with these services. And even if treatment were available in the village, there is no evidence that it would be as easily accessible as in Bethel.65
Neither did Tonya demonstrate a clear understanding of the J. children’s needs. When asked what Morris’s needs were, she responded, “Well, if he comes into our house ... that’s when I’ll find out what his needs are.” She also assumed the J. children would be easier to handle now that they are older, stating that “they’ll be, like, mostly on their own with my children.”
Matilda presented evidence that Bethel is well-equipped to address the special needs of the children. Joel’s teacher testified that Joel needs to be in special education programs, and would benefit from being taught by certified teachers. She expressed doubt that many preschool programs in villages were taught by certified teachers. Morris attends counseling in Bethel with his behavioral health clinician. But for village-based clients, wellness counselors with less training than Morris’s current counselor provide the ongoing counseling. These wellness counselors sometimes do not live in the villages. There was evidence that if Morris had to change clinicians, there would likely be some regressive behavior before a new therapeutic relationship could be established. Sara also requires mental health services to meet her needs.
A home study of Matilda’s home describes Bethel as having “a full range of health care, mental health care, educational, religious, communications, and social services.” The children’s teachers indicated that Joel and Morris’s special education needs can be met by the Bethel school district. Morris’s counselor’s testimony suggests that Bethel also has the behavioral health care facilities necessary to meet the J. children’s needs. A 2002 Catholic Social Services adoption home study noted Matilda’s ability to meet the children’s medical and emotional needs. Morris’s current and Sara’s former behavioral health clinician indicated that the children *1031have made gains in therapy and behavior directly related to Matilda’s care. Morris’s former teachers agreed.
Based on this evidence, the superior court did not clearly err in finding that the children’s special needs could be met in Bethel, but not in the village.
3. The superior court did not err in finding that OCS made adequate efforts under ICWA to provide a statutorily preferred placement.
The tribe also argues that the superior court erred in finding that OCS made adequate efforts under ICWA to provide the children with a statutorily preferred placement. The tribe does not assert that this argument depends on the application of the prevailing social and cultural standards of the Indian community.'
Four out of the eight placements for Morris and Sara during the six years since their removal from their parents have been with relatives.66 OCS compiled a list of eighteen potential relative placements. It contacted the tribes thirty-two times, not including contacts with individual relatives and the biological parents. Ms. Short, the J. children’s original OCS social worker, testified that she exhausted efforts to find relative placements before placing the children with a non-Native family. Ms. Weston-Smith, the OCS worker assigned to the case in April 2003, testified that the tribes were informed at all times that OCS was looking for permanent placement. She also testified that OCS was guided by prevailing Yup’ik social and cultural standards in its search for a suitable placement meeting the preference criteria.
The children’s placement history also supports a finding that OCS made active efforts to find preferred placements. OCS initially placed Morris and Sara with a relative in Bethel but soon removed them after discovering that the relative had a history with child protective services. The children were then placed with relatives in Kasigluk for eighteen months before returning to their biological parents. After removal from their biological parents’ care, Joel’s medical problems required him to live close to a hospital, and he was placed in a non-Native foster home. Morris and Sara were1 placed with relatives until reports of harm required their removal and eventual placement with Joel under Matilda’s care.
There was evidence that while the children were in Matilda’s care, OCS continued to make substantial efforts to find relative placements. OCS considered and rejected placements with both paternal and maternal grandparents because the biological parents and other family members with criminal histories were living in those households. OCS eventually placed the children with relatives Jake and Ruby B., but had to remove them when Joel had to be hospitalized and Ruby B. informed OCS that the J. children, together with five other children living with them, were too much work for her. Other relatives were also disqualified for placement based on either their own criminal history or the criminal history of an adult living in the home.
OCS asked Frank and Tonya B. to be a temporary placement in late 2000, but they declined, stating that it would be too much work. Sometime between January and August of 2001, OCS contacted them again to discuss permanent placement, but Tonya again stated they did not want the J. children. The tribe’s contention that OCS’s failure to initiate more contact with Frank and Tonya after being rebuffed twice shows a lack of adequate efforts under ICWA is unconvincing. In January 2002 OCS contacted the tribe and was informed by counsel that all relative and tribal placements had been exhausted.
Based on this evidence, the superior court did not clearly err in finding that OCS made active efforts to find a statutorily preferred placement for the children.
4. The superior court did not err in finding that Matilda could adequately meet the children’s cultural needs in Bethel.
Finally, the tribe assigns error to the superior court’s finding that Matilda *1032could adequately meet the J. children’s cultural needs in Bethel. The tribe founds this argument on the opinion of its expert witnesses on Yup’ik culture. The tribe argues that “occasional contacts are not enough,” and that “full immersion in the culture is essential to all aspects of a Yup’ik child’s well-being.” The tribe’s standard of adequacy would never allow placement outside the tribe, no matter what the circumstances. The tribe’s evidence on this point may be persuasive in establishing a different order for statutorily preferred placement options, where weight may be given to the tribe’s preferences as expressed by resolution.67 But because this aspect of the good cause inquiry does not implicate the suitability of a preferred placement option, it is not governed by the prevailing social and cultural standards of the Indian community. Here, the suitability of Matilda, a non-preferred placement, is governed by state law and state standards. The superior court was therefore not bound to accept the “uncontradicted evidence of Yup’ik village social and cultural standards” as the tribe argues.
The tribe offered Mark John’s expert testimony about the transmission of Yup’ik cultural values. He testified that a child growing up in Bethel could learn Yup’ik culture and values with exposure to language and Yup’ik elders, and adult male Yup’ik role models for the boys. Sara is enrolled in Yup’ik immersion school and speaks Yup’ik better than many of her Yup’ik friends at school. Morris’s school has Yup’ik classes two to three times a week and tries to incorporate Yup’ik culture ’ into the curriculum. Matilda has spoken to a number of Yup’ik coworkers who are willing to serve as male role models for the boys, including their uncle.
John also testified that a non-Yup’ik family would have to make an extra effort, and would need a connection with Yup’ik families willing to help, including taking the children to fish camp. Matilda has contacted the Kasigluk Tribal Council about the best way to maintain the children’s cultural awareness through cultural activities. Matilda has also evinced willingness to maintain contact between the J. children and their relatives. The children currently have both non-Native and Yup’ik friends. They regularly attended fish camp in the summer before trial, and Sara has gone berry-picking. They also participate in Yup’ik dance.
The parties presented conflicting expert testimony about whether the children’s cultural needs could be met in Bethel. Dr. Roll testified that the children could experience several problems relating to cultural identity, including erosion of language skills, identity confusion, cultural diffusion, and identification with the aggressor. But Dr. Roll had neither visited Bethel nor examined the J. children. Dr. Maclan is a clinical psychologist familiar with Morris and Sara, the J. children’s school, history, and home. Dr. Maclan testified that many problems with cultural identity arise when a child has had no contact with the non-dominant culture and then has to deal with negative stereotypes after realizing that he or she belongs to that group. Dr. Maclan testified that this was not a danger for the J. children, who understand that they are Yup’ik. The superior court evidently credited Dr. Maclan’s testimony. Its determination of credibility between competing experts is a factual finding, which we review for clear error.68 We are not “left with a definite and firm conviction that a mistake has been made”69 by the trial court in crediting Dr. Maclan’s testimony.
The tribe makes much of Matilda’s testimony to the effect that the children cannot truly understand their culture under her tutelage and with limited opportunity to participate in village life. We interpret this to be merely a recognition that this will be a difficult process and that while she can provide some cultural opportunities, she cannot recreate the cultural experience of living in a Yup’ik village. But this does not mean that she will be unable to meet the children’s *1033cultural needs, nor does it' disqualify her altogether from adopting the children.
In Adoption ofN.P.S.,70 we held that good cause existed to deviate from ICWA’s preferences despite cultural disadvantages when the non-preferred placement “is minimally capable of providing for [the child’s] cultural needs.”71 Matilda is much better suited to meet the children’s cultural needs than the placement challenged in N.P.S. There, we held that regular contact with extended family and time spent in the village was sufficient to “give [the child] an understanding of the lifestyle of the Yup’ik culture as well as promot[e] a positive image of himself as an Alaskan Native.”72 Matilda, in contrast, has demonstrated the ability to utilize a range of resources to introduce the children to their Yup’ik culture.
The superior court did not clearly err in finding that Matilda could adequately meet the children’s cultural needs in Bethel.
IV. CONCLUSION
For these reasons, we AFFIRM the superior court’s finding that good causé existed to deviate from the statutory preferences and its decrees of adoption for the J. children.
BRYNER, Chief Justice, concurring.
. 25 U.S.C. § 1901 et seg. (1978).
. 25 U.S.C. § 1915(a).
25 U.S.C. § 1915 provides in part:
(a) Adoptive placements; preferences
In any adoptive placement of an Indian child under State law, a preference shall be given, in the absence of good cause to the contrary, to a placement with (1) a member of the child's extended family; (2) other members of the Indian child's tribe; or (3) other Indian families.
(b) Foster care or preadoptive placements; criteria; preferences
Any child accepted for foster care or preadop-tive placement shall be placed in the least restrictive setting which most approximates a family and in which his special needs, if any, may be met. The child shall also be placed within reasonable proximity to his or her home, taking into account any special needs of the child. In any foster care or preadoptive placement, a preference shall be given, in the absence of good cause to the contrary, to a placement with—
(i) a member of the Indian child's extended family;
(ii) a foster home licensed, approved, or specified by the Indian child’s tribe;
(iii) an Indian foster home licensed or approved by an authorized non-Indian licensing authority; or
(iv) an institution for children approved by an Indian tribe or operated by an Indian organization which has a program suitable to meet the Indian child’s needs.
(c) Tribal resolution for different order of preference; personal preference considered; anonymity in application of preferences
In the case of a placement under subsection (a) or (b) of this section, if the Indian child’s tribe shall establish a different order of preference by resolution, the agency or court effecting the placement shall follow such order so long as the placement is the least restrictive setting appropriate to the particular needs of the child, as provided in subsection (b) of this section. Where appropriate, the preference of the Indian child or parent shall be considered: Provided, That where a consenting parent evidences a desire for anonymity, the court or agency shall give weight to such desire in applying the preferences.
(d) Social and cultural standards applicable The standards to. be applied in meeting the preference requirements of this section shall be the prevailing social and cultural standards of the Indian community in which the parent or extended family resides or with which the par*1020ent or extended family members maintain social and cultural ties....
. 25 U.S.C. § 1915(d).
. 25 U.S.C. § 1915(a).
.Pseudonyms are used for the J. children, the parents, the adoptive mother, and all other family members.
. C.L. v. P.C.S., 17 P.3d 769, 772 (Alaska 2001); Adoption of N.P.S., 868 P.2d 934, 936 (Alaska 1994).
. L.G. v. State, Dep't of Health & Soc. Servs., 14 P.3d 946, 950 (Alaska 2000); In re Adoption of F.H., 851 P.2d 1361, 1363 (Alaska 1993).
. L.G., 14 P.3d at 950.
. Hamilton v. Hamilton, 42 P.3d 1107, 1111 (Alaska 2002).
. Id.; Fardig v. Fardig, 56 P.3d 9, 11 (Alaska 2002).
. 25 U.S.C. § 1901(4).
. In re Adoption of Bernard A., 77 P.3d 4, 9 (Alaska 2003) (recognizing that "placement preference[s] of the ICWA [are] meant to reverse a pattern of breaking up Indian families and to promote the stability of Indian families”) (internal footnote omitted).
. See H.R. Rep. No. 95-1386, at 24 (1978), U.S.Code Cong. & Admin.News 1978 at 7546.
. We recognize that if one parent is Native and the other is not, the Indian child's extended family may include non-Native members who might argue for preferred placement status under ICWA. Despite this possibility, for ease of discussion we use the term "preferred placement” to denote Native placements as specified by § 1915(a).
. In Mississippi Band of Choctaw Indians v. Holyfield, 490 U.S. 30, 32-37, 109 S.Ct. 1597, 104 L.Ed.2d 29 (1989), the Supreme Court began its discussion of the meaning of the word "domicile” in ICWA with an extended discussion of legislative history. See also id. at 44-45, 109 S.Ct. 1597 ("It is clear from the very text of ICWA, not to mention its legislative history and ' the hearings that led to its enactment, that Congress was concerned with the rights of Indian families and Indian communities vis-á-vis state authorities.”). We therefore consider relevant legislative history in deciding this case.
A majority of the Supreme Court, to discern Congress's intent with respect to a particular federal statute, continue to look either to the "context” of the problem Congress was addressing, and "not just literal text,” City of Rancho Palos Verdes, Cal. v. Abrams, 544 U.S. 113, -, 125 S.Ct. 1453, 1462, 161 L.Ed.2d 316 (2005) (Breyer, J., concurring, joined by O'Connor, Souter, & Ginsberg, JJ.), or to traditional legislative history. Id. at 1463 (Stevens, J., concur-, ring).
. John v. Baker, 982 P.2d 738, 747 (Alaska 1999), cert. denied, 528 U.S. 1182, 120 S.Ct. 1221, 145 L.Ed.2d 1121 (2000).
. 25 U.S.C. § 1915(d).
. 25 U.S.C. § 1915(a).
. See Op. at 1034.
. One commentator who argues that the prevailing social and cultural standards ought to apply to the good cause inquiry has recognized that the language does not currently support this reading. See Note, The Indian Child Welfare Act: Guiding the Determination of Good Cause to Depart From the Statutory Placement Preferences, 70 Wash. L.Rev. 1151, 1172-73 (1995) ("Congress could clarify this by simply inserting the phrase 'and in determining good cause to the contrary' into § 1915(d).”).
. The concurrence suggests that this reasoning is circular. Op. at 1034-35. It argues that we start from the "premise that § 1915(a)’s good-cause requirement is not part of that provision's preference requirements” — a premise the concurrence disputes. Id. In our view, the plainest reading of the statute warrants that premise. That Congress failed to write the provision in such a way that made it clear that the good cause determination was encompassed by § 1915(d) simply reinforces a conclusion already suggested by the text of the statute.
. See John v. Baker, 982 P.2d 738, 752 (Alaska 1999), cert. denied, 528 U.S. 1182, 120 S.Ct. 1221, 145 L.Ed.2d 1121 (2000).
. Guidelines for State Courts; Indian Child Custody Proceedings, 44 Fed.Reg. 67,584 (Bureau of Indian Affairs Nov. 26, 1979).
. See, e.g., John, 982 P.2d at 747 n. 33 (according BIA Guidelines "important but not controlling significance"); In re Adoption of F.H., 851 P.2d 1361, 1364 (Alaska 1993) ("Although the Guidelines do not have binding effect, this court has looked to them for guidance.”).
. Montana v. Blackfeet Tribe of Indians, 471 U.S. 759, 766, 105 S.Ct. 2399, 85 L.Ed.2d 753 (1985).
. South Carolina v. Catawba Indian Tribe, Inc., 476 U.S. 498, 506, 106 S.Ct. 2039, 90 L.Ed.2d 490 (1986).
. Id. at 506-07, 106 S.Ct. 2039 (reading the Termination Act to avoid a "contorted construction ... that conflicts with the central purpose and philosophy of the ... Act” and incongruity within the Act); Oregon Dep’t of Fish & Wildlife v. Klamath Indian Tribe, 473 U.S. 753, 774, 105 S.Ct. 3420, 87 L.Ed.2d 542 (1985) ("[E]ven though legal ambiguities are resolved to the benefit of the Indians, courts cannot ignore plain language that, viewed in historical context and given a fair appraisal, clearly runs counter to a tribe’s later claims.”) (internal quotations omitted); see also South Dakota v. Yankton Sioux Tribe, 522 U.S. 329, 348-49, 118 S.Ct. 789, 139 L.Ed.2d 773 (1998) (examining historical context of treaty, considering maxim that statutes ought not be read so as to render words redundant, and referring to analogous precedent in concluding that its reading of statute's plain language was "reasonable interpretation”).
. H.R. Rep No. 95-1386, at 24 (1978), U.S.Code Cong. & Admin.News 1978 at 7546 (emphasis added).
. H.R.Rep. No. 95-1386, at 11, U.S.Code Cong. & Admin.News 1978 at 7533 (emphasis added).
. 25 U.S.C. § 1901(5) (1978).
. 25 U.S.C. § 1902 (1978).
. H.R.Rep. No 95-1386, at 23, U.S.Code Cong. & Admin.News 1978 at 7546.
. The tribe argues that this argument is founded on the unwarranted assumption that all Indian communities will invariably oppose outside placements. But the argument merely recognizes that such an application of the social and cultural standards would give tribes power to veto a good cause determination in any case they choose to contest. We see little difference between granting an interested parly a veto and complete nullification of the provision.
. See 25 U.S.C. § 1911(c) (1978) ("In any State court proceeding for the foster care placement of, or termination of parental rights to, an Indian child, the Indian custodian of the child and the Indian child's tribe shall have a right to intervene at any point in the proceeding.”).
. Alaska Adoption R. 11(f).
. Guidelines for State Courts; Indian Child Custody Proceedings, 44 Fed.Reg. 67,584, 67,595 (Bureau of Indian Affairs Nov. 26, 1979).
. See id. at 67,584.
. See AS 47.05.065(5)(c) C'[I]t is important to provide for an expedited placement procedure to ensure that all children ... are placed in permanent homes expeditiously."); S.H. v. State, DFYS, 42 P.3d 1119, 1125 (Alaska 2002) ("The timeliness of a permanent stable placement for the children is paramount....”).
. Matter of Baby Boy Doe, 127 Idaho 452, 902 P.2d 477 (1995).
. Id. at 487 (emphasis added).
. Id.
. See id.
. Id. at 488 (citing Matter of Custody of S.E.G., 521 N.W.2d 357, 364 (Minn.1994)). We discuss S.E.G. below.
. Id.
. Id. at 488-89.
. Id.
. In re Jullian B., 82 Cal.App.4th 1337, 99 Cal.Rptr.2d 241, 250 (2000).
. Id. at 249.
. Id. at 250.
. The trial court denied the preferred placement based on a statutory disqualification resulting from a forty-year-old criminal conviction. Id. at 249-50. The court held that no good cause to deviate from the preferred placement existed unless the appropriate agency requested waiver of the disqualification or explained why it did not, based on the facts of that case. Id. at 250.
. Guidelines for State Courts; Indian Child Custody Proceedings, 44 Fed.Reg. 67,584, 67,594 (Bureau of Indian Affairs Nov. 26, 1979).
. Id. at 67,584 (citing S.Ref. No. 95-597, at 17 (1977)).
. L.G. v. State, Dep’t of Health & Soc. Servs., 14 P.3d 946, 952-53 (Alaska 2000) ("[T]he primary reason for requiring qualified expert testimony in ICWA termination proceedings was to prevent courts from basing their decisions solely upon the testimony of social workers who possessed neither the specialized professional education nor the familiarity with Native culture necessary to distinguish between cultural variations in child-rearing practices and actual abuse or neglect.") (emphasis in original).
. Id. at 953 (holding that "where there is clear evidence that a child faces a serious risk of physical neglect if she remains in her parent's care, a trial judge may terminate parental rights without hearing testimony from an expert in Native cultures”).
. See Guidelines for State Courts, 44 Fed.Reg. at 67,594 ("In a few cases a child may need highly specialized treatment services that are unavailable in the community where the families who meet the preference criteria live. Paragraph (ii) recommends that such considerations be considered as good cause to the contraiy.”).
. Op. at 1035.
. Id.
. Op. at 1037.
. Op. at 1037.
. Id.
. Matter of Custody of S.E.G., 521 N.W.2d 357, 364 (Minn.1994).
. Id.
. Id. at 364 & n. 7 (quoting Guidelines for State Courts, 44 Fed.Reg. at 67,594).
. We note that despite its disagreement over what standard applies to the good cause determination, the S.E.G. court might reach the same result in this case. In S.E.G., the finding of good cause was rejected because the children's special needs were not established by expert testimony from persons knowledgeable about Native culture. S.E.G., 521 N.W.2d at 364. Here, the children's needs were established through the testimony of Dr. Maclan, who has extensive experience studying and working with Native children, and Jennifer Cashion, whose eight years of experience as a counselor have exposed her to "significant contact with Native children.” In addition, there was testimony that three of the social workers who worked on this case were Yup'iks.
. See Adoption of N.P.S., 868 P.2d 934, 938 (Alaska 1994).
. Although the record is unclear, it appears that at the most, one of Joel’s placements has been in a relative home.
. See 25 U.S.C. § 1915(c).
. Knutson v. Knutson, 973 P.2d 596, 599-600 (Alaska 1999) ("It is the function of the trial court, not of this court, to judge witnesses' credibility and to weigh conflicting evidence.").
.Matter of J.W., 921 P.2d 604, 606 (Alaska 1996).
. Adoption of N.P.S., 868 P.2d 934. (Alaska 1994).
. Id. at 938.
.Id.
. 25 U.S.C. § 1915(a).