Western Watersheds Project v. Salazar

Under BLM's (defendant) Fundamentals of Rangeland Health regulations, Idaho's regional standards required measurable progress toward rangeland health, and permits had to ensure compliance; despite widespread violations, BLM's adaptive-management program let it tolerate ongoing noncompliance indefinitely under a vague over-time standard with no mandated consequence, and BLM renewed permits with loosened restrictions during critical sage-grouse seasons even though the applicable resource-management plan prioritized protecting the species. BLM's environmental assessments for the renewals lacked sufficient cumulative-impact analysis. Western Watersheds Project (plaintiff) sued and moved for partial summary judgment.

Whether an agency's interpretation of its own environmental regulations is entitled to judicial deference when that interpretation is inconsistent with the regulations themselves.