The U.S. Forest Service has agreed re-evaluate cattle grazing in parts of the San Jacinto Mountains after three environmental groups raised concerns that the animals could be damaging habitat needed by bighorn sheep and an endangered butterfly.
The decision affects about 50,000 acres of public land near the intersection of Highways 74 and 371, where ranchers have had permits to graze cattle.
In October, San Bernardino National Forest officials decided to let grazing continue in the area. The Western Watersheds Project, the Sierra Club and the Center for Biological Diversity filed an administrative appeal.
The groups contend an environmental assessment used to support the grazing decision did not address effects on habitat used by peninsular bighorn sheep and the Quino checkerspot butterfly, said Michael Connor, California director of the watershed group.
Shortly after Christmas, the Forest Service agreed to analyze how grazing affects the two species and to look for ways to reduce harm, said John Miller, a San Bernardino National Forest spokesman. The service will do wildlife surveys.
Grazing, which has been permitted there for a century, will continue in the area, Miller said. It is allowed under permits held by Rouse Paradise and Wellman ranches.
Measures may include fencing to keep cattle away from the more sensitive areas, he said.
Connor said cattle and bighorn sheep feed on the same limited supply of plants.
"And butterfly eggs and the larvae are on the plants that get eaten or trampled by the cattle," he said.
Cattle also stray from designated grazing areas and foul streams in the upper Palm Canyon area, he said.
The peninsular bighorn sheep population dwindled to less than 300 in the late 1990s and is now considered an endangered population.
The Quino checkerspot butterfly is found only in Riverside and San Diego counties but once was lived throughout Southern California.
Reach David Danelski at 951-368-9471 or ddanelski@PE.com