Appeal from the United States District Court for the District of Idaho D.C. No.4:08-cv-00363-EJL Edward J. Lodge, District Judge, Presiding
The opinion of the court was delivered by: Silverman, Circuit Judge:
Argued and Submitted December 13, 2010-Pasadena, California
Before: Alex Kozinski, Chief Judge, Mary M. Schroeder, Harry Pregerson, Stephen Reinhardt, Pamela Ann Rymer, Barry G. Silverman, Susan P. Graber, M. Margaret McKeown, Kim McLane Wardlaw, Johnnie B. Rawlinson and Jay S. Bybee, Circuit Judges.
Opinion by Judge Silverman
Today we revisit our so-called "federal defendant" rule, which categorically prohibits private parties and state and local governments from intervening of right on the merits of claims brought under the National Environmental Policy Act of 1969 ("NEPA"), 42 U.S.C. -§-§ 4321 et seq. Because the rule is at odds with the text of Federal Rule of Civil Procedure 24(a)(2) and the standards we apply in all other intervention of right cases, we abandon it here. When construing motions to intervene of right under Rule 24(a)(2), courts need no longer apply a categorical prohibition on intervention on the merits, or liability phase, of NEPA actions. To determine whether a putative intervenor demonstrates the "significantly protectable" interest necessary for intervention of right in a NEPA action, the operative inquiry should be, as in all cases, whether "the interest is protectable under some law," and whether "there is a relationship between the legally protected interest and the claims at issue." Sierra Club v. EPA, 995 F.2d 1478, 1484 (9th Cir. 1993). Since the district court applied the "federal defendant" rule to prohibit intervention of right on the merits in this NEPA case, we reverse and remand so that it may reconsider the putative intervenors' motion to intervene.
This action arises out of the Forest Service's adoption of a travel plan that designated 1,196 miles of roads and trails for use by motorized vehicles in the Minidoka Ranger District of Idaho's Sawtooth National Forest. Two conservation groups, the Wilderness Society and Prairie Falcon Audubon, Inc., claim that the Forest Service violated NEPA by, among other things, failing to prepare an Environmental Impact Statement and failing to consider reasonable alternatives to the travel plan that would protect certain ecologically sensitive water-sheds and wildlife habitats within the District. Their complaint seeks declaratory and injunctive relief invalidating the travel plan, limiting motorized vehicles to previously authorized routes, and prohibiting off-road vehicles from traveling outside designated routes, pending compliance with NEPA and other environmental statutes.
The issue central to this appeal arose when three groups representing recreation interests, the Magic Valley Trail Machine Association, Idaho Recreation Council, and Blue Ribbon Coalition, Inc., moved to intervene to counter the conservation groups' contention that the Forest Service's plan was too accommodating to users of motorized vehicles. The conservation groups opposed intervention, and the Forest Service took no position on the issue. Applying our Circuit's "federal defendant" rule, the district court denied intervention of right. The district court also denied permissive intervention on the grounds that the recreation groups had not adequately participated in the administrative process and "would not add any further clarity or insight" to the litigation.
The recreation groups appealed, arguing that the district court erred in failing to consider limited intervention and abused its discretion in denying permissive intervention. They also urged us to consider modifying or eliminating the "federal defendant" rule. A three-judge panel of our court ordered the parties to brief whether the court should review the case en banc to consider abandoning the rule. The recreation groups again urged the court to do so. The conservation groups took no position on the propriety of the rule. We granted en banc review. We have jurisdiction pursuant to 28 U.S.C. -§ 1291. See Forest Conservation Council v. U.S. Forest Serv., 66 F.3d 1489, 1491 n.2 (9th Cir. 1995) (citing Sagebrush Rebellion, Inc. v. Watt, 713 F.2d 525, 527 (9th Cir. 1983)).
II. INTERVENTION OF RIGHT IN NEPA CASES
 Federal Rule of Civil Procedure 24(a)(2) requires a court, upon timely motion, to permit intervention of right by anyone who "claims an interest relating to the property or transaction that is the subject of the action, and is so situated that disposing of the action may as a practical matter impair or impede the movant's ability to protect its interest, unless existing parties adequately represent that ...