concurring in the judgment only:
I concur with the majority's decision to affirm the court of appeals' judgment upholding the trial court's order granting summary judgment in this case. However, I believe that the majority's reasoning departs from well-established principles of deed interpretation used in Colorado, and conflicts with the reasoning adopted by the majority of courts that have previously considered this issue. In my opinion, the majority improperly considers extrinsic evidence of Colorado history, custom, and usage in determining the meaning of the term minerals, as used in the general deed reservation in this case. Therefore, I respectfully decline to join the majority opinion.
A.
General Principles of Deed Interpretation
The majority affirms the court of appeals' decision upholding the trial court's grant of summary judgment in this case. Maj.Op. at 854. In doing so, the majority determines that the issue of whether the term minerals includes oil and gas is a legal, rather than a factual question, thus concluding that a trial in this case is unnecessary. Id. However, in direct contradiction to the decisions below, which hold that the term minerals is unambiguous as a matter of law, the majority holds that the term minerals is "not inherently unambiguous" and that extrinsic evidence may be required to determine the parties' intent under certain circumstances. Id. at 349. The majority then relies on historical information concerning custom and usage to determine that the term minerals has a well-settled meaning that includes oil and gas. Id. As discussed below, this reasoning conflicts with general principles of deed interpretation and with the majority of other jurisdictions that have considered this issue.
It is well established in Colorado that a primary goal in interpreting a deed is to effectuate the parties' intent, and that such intent may be ascertained by reviewing extrinsic evidence when a deed is found to be ambiguous. Lazy Dog Ranch v. Telluray Ranch Corp., 965 P.2d 1229, 1235 (Colo.1998); Pepcol Mfg. Co. v. Denver Union Corp., 687 P.2d 1310, 1313 (Colo.1984). However, when a deed is unambiguous, the intentions of the parties must be determined from the deed itself, and consideration of extrinsic *355evidence of intent is not permissible. O'Brien v. Village Land Co., 794 P.2d 246, 249 (Colo.1990); First Nat'l Bank v. Allard, 182 Colo. 297, 301, 513 P.2d 455, 457 (1973); Simson v. Langholf, 133 Colo. 208, 216, 293 P.2d 302, 307 (1956), Brown v. Kirk, 127 Colo. 453, 456, 257 P.2d 1045, 1046 (1953).
The issue of whether an ambiguity exists is a matter of law to be determined by the court. Pepcol, 687 P.2d at 1314. In making this determination, a court may conditionally admit extrinsic evidence on the issue of ambiguity to determine whether a deed is ambiguous. Lazy Dog, 965 P.2d at 1235; O'Brien, 794 P.2d at 249 n. 2. However, we have held that "lin cases where the language specifically and completely addresses the issue at hand, there will be no need to look to the surrounding cireumstances." Lazy Dog, 965 P.2d at 1236. In such cases, courts need not consider extrinsic evidence for purposes of determining ambiguity, nor for purposes of ascertaining the parties' intent.1
The majority opinion fails to follow these general principles of deed interpretation. Without regard to whether the language in the deed reservation in this case completely addresses whether oil and gas are included as minerals, the majority determines that the term minerals has a well-settled meaning that includes oil and gas. Maj. Op. at 349. In doing so, the majority relies on historical information concerning custom and usage to determine both the ambiguity of the term minerals and its meaning.
Furthermore, by relying on such information to ascertain the meaning of the term minerals, the majority determines an issue of fact properly determined by a trial court. See Pepcol, 687 P.2d at 1314 (holding that once a provision is determined to be ambiguous, its meaning is an issue of fact to be determined by a trial court's review of extrinsic evidence). Indeed, the custom and usage information relied upon by the majority is precisely the type of evidence the trial court barred by its grant of summary judgment.2 Thus, the majority opinion has the effect of denying the landowners the opportunity to present their evidence concerning custom and usage, while at the same time relying on its own descriptions of custom and usage.
B.
The Majority Rule
The majority's reasoning also conflicts with the so-called "Majority Rule," which holds that the term minerals is unambiguous as a matter of law. In contrast to the Majority Rule, the majority opinion holds that the term minerals is "not inherently unambiguous," and that extrinsic evidence of intent may be required in certain cireumstances. Maj. op. at 349. The majority opinion then concludes, based on its review of Colorado history, custom, and usage, that the term minerals includes oil and gas. Id.
The courts that have adopted the Majority Rule have specifically declined to consider such evidence and hold that the term miner*356als, as used in a deed reservation, is unambiguous as a matter of law. See Anschutz Land & Livestock Co. v. Union Pac. R.R. Co., 820 F.2d 338, 343-44 (10th Cir.1987) (adopting the district court's reasoning in holding that a reservation of "other miner als" is unambiguous under Utah law); Union Pac. Land Res. Corp. v. Moench Inv. Co., 696 F.2d 88, 93 (10th Cir.1982) (holding that the phrase "coal and other minerals" as used in a deed reservation, is unambiguous under Wyoming law); Amoco Prod. Co. v. Guild Trust, 636 F.2d 261, 264 (10th Cir.1980) (agreeing with the district court's conclusion that the reservation of "coal and other minerals" is unambiguous under Wyoming law); Spurlock v. Santa Fe Pac. R.R. Co., 143 Ariz. 469, 694 P.2d 299, 308-09 (Ct.App.1984) (holding the term minerals unambiguous as a matter of law after considering rationales of courts in other jurisdictions); Miller Land & Mineral Co. v. State Highway Comm'n, 757 P.2d 1001, 1002-03 (Wyo.1988) (holding that a reservation of "all minerals and mineral rights under said lands" was clear and unambiguous)3
In Miller Land, the Supreme Court of Wyoming held that a reservation of "all minerals and mineral rights existing under said ... lands" was clear and unambiguous as a matter of law. 757 P.2d at 1002-03. The court found no need to consider extrinsic evidence of intent. See id. at 1002. The court rejected the minority position that a general reservation of "all minerals" is inherently ambiguous, stating that those courts "have traveled over a long and tortuous path in a complex and hopeless search to discover the particular minerals the parties intended to reserve." Id. The court found that such an approach would result in title uncertainty and the need to litigate each mineral reservation to determine which minerals it encompasses. See id.
In Amoco, the Tenth Circuit interpreted reservations identical to those in this case. 636 F.2d at 262-63. The court there held the reservation language to be unambiguous as a matter of law and noted that authority to the contrary was very limited. See id. at 264. Accordingly, the court upheld the district court's application of the parol evidence rule in excluding extrinsic evidence of intent. See id. at 263. Similarly, in Anschutz, the Tenth Circuit found no ambiguities in reservations of "all coal and other minerals within or underlying said land" and of "all oil, coal and other minerals." Anschutz, 820 F.2d at 343-44, The court there held that the reservation language was broad enough to encompass oil and gas as a matter of law, thereby precluding the consideration of extrinsic evidence of intent. See id. at 344.
The majority opinion correctly notes that an established rule of law is important in providing a reliable means for ascertaining mineral ownership and that the use of extrinsic evidence to ascertain the parties' intent creates complex litigation issues involving endless and unreliable factual determinations. Maj. Op. at 353; see John S. Lowe, What Substances Are Minerals?, 30 Rocky Mtn.Min.L.Inst. 2-1, 2-10 (1985). Because the deeds in question are often over one hundred years old, and the parties to the original deeds are usually unavailable, successor parties in interest must present historical documents, expert testimony, and other unreliable and burdensome evidence to attempt to establish intent. See Eugene O. Kuntz, The Law Relating to Oil and Gas in Wyoming, 3 Wyo. L.J. 107, 114 (1949). However, although the majority opinion ree-ognizes that such an approach is ineffective, it nonetheless holds that such extrinsic evidence may be considered under certain circumstances, without providing further guidance as to when such cireumstances might arise. Maj. Op. at 349. Indeed, in this case, *357the majority considers historical information concerning Colorado custom and usage in making its determination, while preventing the landowners from introducing precisely the same type of evidence.
I would employ the reasoning of courts applying the Majority Rule and would hold that the term minerals, as used in a general deed reservation, is unambiguous as a matter of law. As such, I would find no need to consider the type of factual, historical information discussed in the majority opinion and proffered by the landowners in this case to determine the meaning of the term minerals. Rather, a review of Colorado case law and cases in other jurisdictions would guide my determination of this issue of law.
In Colorado, the term minerals, as used in a deed reservation, has not been limited to those substances specifically listed in the reservation. See, e.g., Gilpin Inv. Co. v. Perigo Mines Co., 161 Colo. 252, 258, 421 P.2d 477, 480 (1966) (holding that the use of the term "mineral rights" in a deed reservation included flecks of gold and other valuable minerals remaining on the surface after rains and surface waters had washed gravel down the slope of the property); Calvat v. Juhan, 119 Colo. 561, 566, 206 P.2d 600, 608 (1949) (holding that gas, though not specifically enumerated, was among those minerals excluded by a deed reservation).
Similarly, courts in other jurisdictions have held that a general reservation of minerals includes minerals not mentioned specifically in a reservation. Amoco, 636 F.2d at 264 (noting that Western states have adopted broad, all-inclusive interpretations of the term minerals). Several courts have specifically held that the term minerals includes oil and gas. Id.; Anschutz, 820 F.2d at 343; Missouri Pac. R.R. Co. v. Strohacker, 202 Ark. 645, 152 S.W.2d 557, 561 (1941).
I am persuaded by the reasoning of the Tenth Cireuit cases that have interpreted reservations identical to those in this case as including ofl and gas. See Anschutz, 820 F.2d at 343 (holding that the reservations were sufficient to encompass oil and gas interests as a matter of law); Amoco, 636 F.2d at 264 (holding that the reservation of "coal and other minerals" unambiguously includes oil and gas). In Amoco, the court cited several academic sources indicating that the majority of states have held that a mineral reservation includes oil, gas and petroleum products, unless the language in the instrument indicates otherwise. Amoco, 636 F.2d at 264; see 1 Howard R. Williams & Charles J. Myers, Oil and Gas Law § 219.1 (1978); Richard W. Hemingway, The Law of Oil and Gas § 1.1 (1971). The language of the deed in the present case indicates no restriction on the term minerals. Accordingly, I1 would hold that the term minerals, as used in the general deed reservation in this case, includes oil and gas.
C.
Conclusion
I agree with the majority's decision to affirm the court of appeals' judgment upholding a finding of summary judgment in this case. However, because the majority opinion departs from well-established principles of deed interpretation and the Majority Rule adopted in other jurisdictions, I cannot join its opinion.
I would hold that the term minerals, as used in the general deed reservation in this case, is unambiguous as a matter of law. Accordingly, I would hold that the trial court properly disregarded extrinsic evidence proffered by the landowners concerning Colorado history, custom, and usage.
I would further hold that the term minerals, as used in the general deed reservation in this case, includes oil and gas. Therefore, like the majority, I would affirm the judgment of the court of appeals upholding the trial court's judgment.
I am authorized to say that Chief Justice MULLARKEY and Justice COATS join in concurring with the judgment only.
. I note the Tenth Circuit's use of extrinsic evidence to ascertain the ambiguity of a mineral reservation in United States v. 1,253.14 Acres of Land, 455 F.2d 1177 (10th Cir.1972). However, this approach is inconsistent with later Tenth Circuit cases that have determined that the term minerals is unambiguous as a matter of law. See Anschutz Land & Livestock Co. v. Union Pac. R.R. Co., 820 F.2d 338, 343 (10th Cir.1987); Amoco Prod. Co. v. Guild Trust, 636 F.2d 261, 264 (10th Cir.1980).
. The record demonstrates that the landowners attempted to present thousands of pieces of evidence concerning the parties' intent at the time of the conveyance, Colorado history, custom and usage, and early Union Pacific Railroad operations. See R. at 834. The tendered evidence included numerous geological articles, treatises and books concerning mining, mineral terminology, and early oil and gas development in Colorado, letters exchanged between the parties around the time of the conveyance, an early Colorado statute, books concerning the history of Colorado and of Weld County, hundreds of newspaper articles dated around the time of the conveyance, historical documents concerning early Union Pacific Railroad operations, and guides to Union Pacific Railroad lands from the late 1800s. See id.
The majority opinion likewise relies on treatises concerning mineral terminology and oil and gas law, as well as the same early Colorado statute sought to be introduced by the landowners. Maj.Op. at 349-351. The majority also supports its holding through its description of the history of the Union Pacific Railroad lands in this case. See id. at 352-353.
. Cf. United States v. Hess, 194 F.3d 1164, 1174 (10th Cir.1999). In Hess, the Tenth Circuit held a reservation of "all minerals" in a land exchange patent to be ambiguous as applied to gravel deposits near the surface of the property in question. Id. Hess is distinguishable from the case at bar because it involved the interpretation of a reservation in a federal exchange patent rather than a private deed reservation. See id. The court in Hess noted the unique treatment of a mineral reservation in an exchange patent in relation to such a reservation in a land grant patent. See id. at 1171. Also, the court in Hess based its holding on federal law as determined in reference to state law, and looked to Congress's intent in passing the Indian Reorganization Act. See id. at 1173.