BOISE, Idaho (AP) — An Idaho environmental group has sued the U.S. Forest Service again, targeting its decision allowing livestock grazing in a central Idaho river valley that's home to critical habitat for endangered bull trout.Western Watersheds Project filed its lawsuit Tuesday in U.S. District Court in Boise, alleging Endangered Species Act violations.

The group is challenging livestock grazing on three allotments in the Salmon-Challis National Forest in the Little Lost River watershed. It contends cattle wade within the stream beds of the Little Lost River and graze its banks, trampling fish nests, displacing juvenile fish and harassing spawning adult fish.

The environmentalists argue the Forest Service's decision to allow grazing here violates the ESA because the agency is relying on, among other things, "incorrect factual assumptions" and failed methods to effectively control livestock.