According to the plaintiffs, the project’s significant effects on wildlife required that BLM do a full environmental impact statement (EIS), rather than a more limited environmental assessment (EA). The district court ruled, however, that there were no sage grouse mating grounds (called "leks") in the project area, existing highways separated leks from the project boundaries and, in any event, the BLM had implemented mitigation measures that would reduce impacts on sage grouse.
Accordingly, the court said the plaintiffs had not raised substantial questions that the wind power project would cause significant deterioration to the sage grouse population and habitat, and therefore a more detailed EIS was not required.
The plaintiffs also argued that an EIS was necessary due to the presence of the Rose Guano Cave nearby (a seasonal roost to more than a million Brazilian free-tailed bats during the August-September migration season) and the likelihood that bats would fly near the project site while foraging or migrating.
The court disagreed and said that BLM had provided "persuasive scientific data" that the impact on bats, particularly with mitigation measures imposed on the project, will not be significant and, therefore BLM was not required to do an EIS.