BOISE, Idaho (AP) — Federal wildlife and agricultural agencies are denying claims by environmental groups that a sheep research station on the Idaho-Montana border is harming the region's grizzly bear population.

Western Watersheds Project and four other environmental groups sued the U.S. Fish and Wildlife Service and other federal agencies in May, contending the biological opinion for the U.S. Sheep Experiment Station in the Centennial Mountain Range failed to account for several grizzly bear deaths and that the region's grizzly bear population is being harmed.

On Tuesday, attorneys for the U.S. Fish and Wildlife Service filed their response to the lawsuit, denying all of the claims and saying the biological opinion speaks for itself. The experimental station was established in 1918 for breeding and grazing research.