Sierra Club v. Clark

Unrestricted off-road vehicle (ORV) use in Dove Springs Canyon, a small portion (0.025%) of the vast BLM-administered California Desert Conservation Area, caused severe local environmental harm; the Sierra Club (plaintiff) petitioned the Secretary of the Interior (defendant) to close the canyon to ORV use, and when the Secretary declined, sued, arguing the failure to close the canyon violated federal executive orders and FLPMA regulations requiring closure of areas suffering 'considerable adverse effects' from ORV use. The district court granted the Secretary summary judgment, and Sierra Club appealed, arguing a CEQ memo interpreting the closure standard was entitled to deference and that the Secretary's broader interpretation was unreasonable.