What are the arguments that the EIS should take a hard look only at the relevant environmental consequences?

When considering an application for a special use permit to
develop and operate a ski resort at Sandy Butte, a mountain
in Washington that is part of a national forest, the Forest
Service prepared an environmental impact statement (EIS).
The EIS recommended the issuance of a special use permit
for what was to be a sixteen-lift ski area, and the forest ser-
vice issued the permit as recommended. Four organizations
sued, claiming that the EIS was inadequate. The lower court
held that the EIS was adequate, but the Court of Appeals
reversed, concluding that the National Environmental Policy
Act required that actions be taken to mitigate the adverse
effects of a major Federal action and that the EIS contain a
detailed mitigation plan.
a. What are the arguments that the EIS should take a hard
look only at the relevant environmental consequences?
b. What are the arguments that the EIS should propose actions
that mitigate the relevant environmental consequences?
c. What should the EIS include in this situation