Conservation groups have filed a notice of intent to sue a pair of federal agencies for their failure to control overgrazing on public lands.
Tonto National Forest is home to many threatened and endangered species.
But the Center for Biological Diversity and Maricopa Audubon Society say the agencies that oversee the forest and its wildlife have not done enough to protect them from cattle grazing along the Salt River and its tributaries.
They say that the Forest Service agreed more than two decades ago to work with U.S. Fish and Wildlife to address the problem, but has not done so.