Three commercial fishing associations appeal the district court’s order denying intervention in an action brought by the United States, as trustee for various Indian tribes, against the State of Washington. The United States and the tribes claimed fishing rights to shellfish. We affirm the district court’s ruling that the motions to intervene were untimely.
FACTS
In 1970, the United States, on its own behalf and as trustee for various Washington State (or “State”) Indian tribes, brought an *1502action against the State to enforce fishing rights reserved by the tribes in a series of treaties signed in the 1850s and negotiated by Isaac Stevens, the first Governor and first Superintendent of Indian Affairs of the Washington Territory (the “Stevens treaties”). See Washington v. Washington State Comm’l Passenger Fishing Vessel Ass’n, 443 U.S. 658, 666-69, 674-679, 99 S.Ct. 3055, 3064-66, 3068-71, 61 L.Ed.2d 823, modified, 444 U.S. 816, 100 S.Ct. 34, 62 L.Ed.2d 24 (1979) (“Passenger Fishing Vessel”). The district court eventually granted the tribes off-reservation fishing rights for salmon and steelhead, allowing state regulation of those rights for conservation purposes only. United States v. Washington, 384 F.Supp. 312 (W.D.Wash.1974), aff'd, 520 F.2d 676 (9th Cir.1975), cert. denied, 423 U.S. 1086, 96 S.Ct. 877, 47 L.Ed.2d 97 (1976). Those Indian tribes fishing under treaty rights could take up to fifty percent of the harvestable fish. Id. at 343. The district court retained continuing jurisdiction over unresolved treaty issues, authorizing the parties to file a “Request for Determination” of any issue concerning the subject matter of the case. Id. at 347. This court and the Supreme Court affirmed in substantial part. United States v. Washington, 520 F.2d 676 (9th Cir.1975), cert. denied, 423 U.S. 1086, 96 S.Ct. 877, 47 L.Ed.2d 97 (1976); Passenger Fishing Vessel, 443 U.S. 658, 99 S.Ct. 3055.
Almost twenty years after the filing of the initial litigation, in 1989 the United States and sixteen Indian tribes (“Tribes”) began a “subproceeding” by filing a Request for Determination and Declaratory and Injunctive Relief, seeking a declaration that their treaty right to take off-reservation fish extended to all species of shellfish found within their traditional fishing grounds. The State filed a response denying the Tribes’ right to shellfish. The district court allowed intervention by several commercial shellfish growers and two private waterfront owners.
In September 1991, the Inner Sound Crab Association (“Inner Sound”), a group of non-Indian commercial dungeness crab fishers in Puget Sound, moved to intervene, arguing that the State would not vigorously defend Inner Sound’s interests. At a pretrial conference on January 27, 1993, the district court denied the motion, instead giving Inner Sound amicus status and a right to receive and comment on all filings in the case. Inner Sound did not appeal.
In September 1993, the district court granted partial summary judgment for the Tribes, ruling that the treaty right to take “fish” includes the right to take shellfish. In January 1994, the court denied a motion for summary judgment by the State of Washington, ruling that the right to take shellfish included the right to harvest shellfish within a tribe’s usual and accustomed fishing areas at any depth. After trial, the district court issued a memorandum opinion in December 1994 reaffirming its rulings that shellfish were fish, and that the Tribes could harvest in deep water. The decision divided the shellfish equally between treaty and non-treaty harvesters, and invited the parties to negotiate an implementation plan. United States v. Washington, 873 F.Supp. 1422, 1430-31, 1445-46 (W.D.Wash.1994). The decision deferred the issue of injunctive relief or any plan of implementation until the court received input from the parties. Id. at 1450.
Three months after the memorandum opinion, in March 1995, the Washington Harvest Divers Association (“Harvest Divers”), an association of commercial harvesters of sea urchins and sea cucumbers (both considered shellfish), moved to intervene. Also, Inner Sound again moved to intervene, this time by a joint motion with the Washington Dungeness Crab Fisherman’s Association (“Dungeness Crab”), an association of active commercial dungeness crab fishers off the coast of Washington. In April 1995, the district court denied both motions and denied amicus status to the applicants for intervention.
On August 25, 1995, the district court entered an order directing the entry of final judgment consistent with the December 20, 1994, memorandum decision.
The three commercial fishers associations (collectively the “Associations”) appeal the denial of their motions to intervene.
*1503DISCUSSION
I. Motions to intervene as of right
This court reviews de novo the denial of a motion to intervene as of right. Sierra Club v. EPA 995 F.2d 1478, 1481 (9th Cir. 1993). The district court’s determination of one part of the test for intervention, timeliness, is reviewed for an abuse of discretion. Id.; Yniguez v. Arizona, 939 F.2d 727, 730-31 (9th Cir.1991).
Rule 24 of the Federal Rules of Civil Procedure provides:
Upon timely application anyone shall be permitted to intervene in an action ... when the applicant claims an interest relating to the property or transaction which is the subject of the action and the applicant is so situated that the disposition of the action may as a practical matter impair or impede the applicant’s ability to protect that interest, unless the applicant’s interest is adequately represented by existing parties.
Fed.R.Civ.P. 24(a)(2). The district court must grant the motion to intervene if four criteria are met: timeliness, an interest relating to the subject of the litigation, practical impairment of an interest of the party seeking intervention if intervention is not granted, and inadequate representation by the parties to the action. Greene v. United States, 996 F.2d 973, 976 (9th Cir.1993). Rule 24(a) is construed broadly in favor of intervention. Id.
Because the Associations do not all make the same arguments regarding their motions to intervene, we address each Association separately.
A. Harvest Divers
This court evaluates three factors to determine whether a motion to intervene is timely: “(1) the stage of the proceeding at which an applicant seeks to intervene; (2) the prejudice to other parties; and (3) the reason for and length of the delay.” United States ex rel. McGough v. Covington Technologies Co., 967 F.2d 1391, 1394 (9th Cir. 1992) (quotations omitted). Delay is measured from the date the proposed intervenor should have been aware that its interests would no longer be protected adequately by the parties, not the date it learned of the litigation. Officers for Justice v. Civil Serv. Comm’n of San Francisco, 934 F.2d 1092, 1095 (9th Cir.1991). Although the length of the delay is not determinative, any substantial lapse of time weighs heavily against intervention. Id. If the court finds that the motion to intervene was not timely, it need not reach any of the remaining elements of Rule 24. United States v. Oregon, 913 F.2d 576, 588 (9th Cir.1990), cert. denied, 501 U.S. 1250, 111 S.Ct. 2889, 115 L.Ed.2d 1054 (1991).
In April 1995, the district court found that the motions were untimely, stating:
Here, the proceeding is at a stage of final implementation. The impact to the movants has been foreseeable since at least 1989, when this sub-proceeding was filed. The proceeding has advanced to a late stage, a stage too late for intervention. In addition, the other parties would be prejudiced by the intervention of these groups. Permitting the movants to enter this litigation would unnecessarily prolong and complicate resolution of the issues at stake. Indeed, the movants really appear to have their own agenda, namely they contest the way that the state manages the NON-tribal 50% [of shellfish], and, in the case of [the parties on appeal], they contest the Indians having a share at all. Therefore, the groups seek redress of an issue not before the Court, and they additionally seek to relitigate an issue that the Court already decided. If they were permitted to intervene and attempted to raise these issues, they would prolong and complicate the case, to the detriment of those parties that have been part of the litigation from the outset.
Finally, no group has stated a satisfactory reason for its delay in attempting to intervene.
1. Stage of proceeding
Harvest Divers moved to intervene three months after the district court issued its memorandum opinion. Harvest Divers argues that it should have been allowed to *1504intervene at that late date because Washington State became “openly antagonistic” toward Harvest Divers only after the memorandum opinion was issued in December 1994, and that the delay in filing should be measured from this date. The recent “open antagonism” Harvest Divers cites, however, simply reflected Washington State’s efforts to implement the trial court’s memorandum opinion.
Harvest Divers’ own documents also indicate that it believed that Washington State was hostile to its interests since long before the final decision. For example, Harvest Divers states that it was afforded no opportunity to participate in Washington State’s preparation for trial or the trial itself; that Washington State has followed a “pro-Indian” policy “by a continuous course of conduct,” and rebuffed all Harvest Divers’ efforts to communicate with its agencies before and after the district court’s decision; and that throughout the litigation, “[t]he policies adopted by the State are to seek accommodation with Indians and use all possible means to achieve that goal. Essentially the State has conceded most of the Tribes’ case by its actions prior to issuance of Judge Rafeedie’s memorandum opinion.” Further, in his declaration supporting the motion to intervene in the district court, Harvest Divers President Tom McMahon stated “We have absolutely no confidence in [the State] to represent our interests. In fact, I believe that their' interests oppose ours based on their actions this past two years.”
Moreover, the issues identified by Harvest Divers are basic to many of the issues decided long before the final decision in the district court. Among other arguments, Harvest Divers contends that the Stevens treaties could not preserve to the Tribes any rights at all in shellfish, and that the treaties could not recognize any Indian authority to regulate the gathering of shellfish by tribal members in off-reservation waters. These issues go to the heart of the case and the interpretation of the Stevens treaties. The period of final implementation is too late a stage of the proceeding to permit intervention to relitigate such basic questions. See Oregon, 913 F.2d at 588 (courts allowing intervention after the entry of consent decrees generally have specified that no previously litigated issues may be reopened).
2. Prejudice to other parties
The district court found that the other parties would be prejudiced by the requested intervention, because intervention would complicate the issues and prolong the litigation. This was not an abuse of discretion. The Harvest Divers’ arguments challenge the very foundation for any allocation of shellfish rights to the Tribes, by questioning whether the Stevens treaties reserved any rights at all to the Tribes. Intervention on the grounds urged by Harvest Divers would upset the delicate balance achieved by the district court after six years of litigation. See id. at 589 (prejudicial to upset a delicate compromise achieved after years of litigation).
3. Reason for and length of delay
The district court found that none of the Associations had stated a satisfactory reason for its delay. On appeal, Harvest Divers argues that it did not move to intervene earlier because the district court denied Inner Sound’s 1993 motion to intervene, and that Harvest Divers filed its motion only when “the full import of the State’s political maneuvering became apparent.” Yet Harvest Divers should not have let the fate of Inner Sound’s motion to intervene govern Harvest Divers’ decision whether to apply for intervention, because its arguments were not identical to those of Inner Sound. Further, even if Harvest .Divers believed that Inner Sound’s arguments adequately represented the interests of Harvest Divers, Harvest Divers could have readily ascertained that Inner Sound did not intend to appeal the denial of its first motion, and therefore should have sought intervention to protect that right to appeal. Moreover, Harvest Divers claims that the State persistently refused to communicate with it about the issues before the court, maintaining that Washington State followed a “pro-Indian” policy and opposed Harvest Divers’ interests throughout.
Assuming that these allegations are true, the association was on notice that it might *1505need to intervene to protect its interests. See Oregon, 913 F.2d at 589 (inquiries and attempts to participate in litigation show awareness that risk exists). The district court’s denial of the earlier motion by a different association thus does not sufficiently explain Harvest Divers’ failure to present its own reasons for intervention.
Because Harvest Divers did not file a motion to intervene until after the district court issued its decision in this case, the other parties would be prejudiced by the requested intervention, and Harvest Divers did not present satisfactory reasons for its substantial delay in filing the motion to intervene, it was not an abuse of discretion for the district court to find that Harvest Divers’ motion to intervene was not timely. We therefore do not reach the remaining elements of Rule 24.
B. Inner Sound
Because Inner Sound appeals from a motion to intervene filed on the same date as Harvest Divers, at first glance it seems the same timeliness analysis should be applied on appeal. Inner Sound, however, seeks a more lenient analysis on two grounds.
The earlier motion. Inner Sound first moved for intervention on September 26, 1991, and the district court denied the motion on January 27, 1993. Inner Sound was granted amicus status and the right to receive and comment on all pleadings. Inner Sound did not appeal this decision, and the earlier motion to intervene is not before us.
Inner Sound attempts, however, to rely on its earlier motion in arguing that its later motion was timely. It seeks to excuse its decision not to appeal the denial of the first motion by stating that it relied on the district court’s assurance that it could again file for intervention. We reject Inner Sound’s attempt to resurrect an earlier, unappealed (and presumably timely) failed motion to intervene, in order to support its argument that a much later motion, filed after the court had reached a decision on the merits, was improperly denied.
Limited intervention. In the district court, Inner Sound’s second motion to intervene stated that it sought intervention
for the limited purpose of participating in the negotiation and formation of those provisions of the Court’s implementation plan ... and any and all proceedings related to the Implementation Plan ---- to participate in negotiation meetings concerning the management and harvest of the dungeness crab resource ... [and] to present argument to the court concerning the implementation plans and to have the right to appeal any final court order concerning such dungeness crab management issues. Finally, applicants seek to appear at any and all proceedings held under this Court’s continuing jurisdiction relating to implementation of the Court’s memorandum opinion and order dated December 20, 1994.
On appeal, Inner Sound states that it seeks to intervene “to participate in this appeal and future subproceedings, as necessary.” Inner Sound argues that the standards for “limited intervention” for the purpose of appeal should apply. A motion to intervene seeking only to participate in the appeal is timely if filed within the time allowed for filing an appeal. McGough, 967 F.2d at 1395.
We decline to apply the timeliness analysis that would apply to an intervention limited to appeal. First, it is disingenuous of Inner Sound to claim that it seeks “limited intervention” when it asked for far more in the district court and, even on appeal, seeks to participate in “future subproceedings” and to “have a voice in the implementation plan,” complaining that it and the other Associations “never had their day in the district court.” Second, at the time Inner Sound filed its motion to intervene, there had been no final judgment in the overall proceeding from which an appeal could be taken. Intervention for the purpose of appeal was thus premature. Third, Inner Sound had no indication that the State would not appeal from a final judgment. Washington State had made “repeated assurances” that it would appeal, and we take judicial notice that the State recently did file an appeal after its motion for reconsideration was denied. United States v. State of Washington, No. 96-35014 (9th Cir. filed Jan. 8, 1996).
*1506We therefore do not address the motion as one for limited intervention, as it was not filed on that basis in the district court, nor does it appear to be so limited on appeal. We instead apply the traditional test of timeliness to Inner Sound’s motion to intervene.
1. Stage of proceeding
The appropriate analysis is the same as that applied to Harvest Divers, and the result is the same. This stage of the proceeding is too late for this motion to intervene.
Inner Sound had reason to believe that the State’s representation was inimical to the association’s interests in 1991. Inner Sound submitted a declaration from its president in the district court stating that “I have experienced great frustration in communicating with the [state] Department of Fish and Wildlife ... during the past year, we have not had the courtesy of being afforded direct communication.” It also attached a declaration from the earlier motion to intervene in September 1991, which stated that Inner Sound sued the State in 1988 over its “sporadic” enforcement against Tribal fishers and because “the State cannot adequately represent the interests of the Inner Sound Crab Association.” Inner Sound cannot now claim, on the ground that it had only recently realized its interests were in jeopardy, that a motion to intervene filed as late as 1995 was timely.
2. Prejudice to other parties
Although Inner Sound purports not to re-litigate issues already decided, it complains that there has been “no historical evidence of tribal participation in the coastal crab fishery ... [which] extend[s] for miles into the Pacific Ocean.” If Inner Sound were allowed to intervene to relitigate this issue, Inner Sound would certainly upset the “delicate balance” achieved by the district court and prejudice the parties by further delay and briefing. See Oregon, 913 F.2d at 589.
3. Reason for and length of delay
Inner Sound argues that one reason for its late motion was the State’s emergency closure of the crab fishery in February 1995, implying that the “premature” closure prompted its motion to intervene one month later. A failure to realize that one’s interests are in jeopardy until very late in the proceedings may make a late motion to intervene “timely.” See Yniguez, 939 F.2d at 735. The closure of the crab fishery, however, was not Inner Sound’s first indication that its interests were threatened. Inner Sound knew that its deep-water fishery was to be shared with the Tribes as early as January 1994, when the district court ruled that the Tribes could harvest any species of shellfish at any depth. That was fourteen months before Inner Sound filed its motion to intervene.
For the reasons stated above, it was not an abuse of discretion for the district court to find that Inner Sound’s motion to intervene was not timely. We therefore need not reach the remaining elements of Rule 24 intervention.
C. Dungeness Crab
Dungeness Crab filed for intervention with Inner Sound in 1995, and shares Inner Sound’s brief on appeal, although unlike Inner Sound it did not file to intervene earlier in the lawsuit. We hold that Dungeness Crab’s motion was properly denied as untimely for the same reasons as was Inner Sound’s, under traditional intervention analysis.
II. Permissive intervention
The district court also denied the Associations’ requests for permissive intervention under Federal Rule of Civil Procedure 24, which provides that a court may permit intervention pursuant to a timely motion
when an applicant’s claim or defense and the main action have a question of law or fact in common---- In exercising its discretion the court shall consider whether the intervention will unduly delay or prejudice the adjudication of the rights of the original parties.
Fed.R.Civ.Pro. 24(b)(2). Permissive intervention requires “(1) an independent ground for jurisdiction; (2) a timely motion; and (3) *1507a common question of law and fact between the movant’s claim or defense and the main action.” Beckman Indus., Inc. v. International Ins. Co., 966 F.2d 470, 473 (9th Cir.), cert. denied, 506 U.S. 868, 113 S.Ct. 197, 121 L.Ed.2d 140 (1992). This court reviews a denial of permissive intervention for an abuse of discretion. Id. at 472.
The district court found that “as shown above, the movant’s motions are not timely, and intervention would cause prejudice to the other parties.” A finding of untimeliness defeats a motion for permissive intervention. Oregon, 913 F.2d at 589. Because we hold that the district court did not abuse its discretion in finding that the motions to intervene were untimely, we affirm the district court’s refusal to exercise its discretion to allow permissive intervention.
CONCLUSION
We affirm the denial of the motions to intervene.