The Peninsular Ranges extend 1,500 km (900 mi) from Southern California to the southern tip of the Baja California peninsula, forming a granitic spine near the western edge of the North American continent. They comprise an intact and rugged wilderness area connecting two countries and some of the richest montane and desert ecosystems in the world that support wideranging, iconic species, including mountain lion, California condor, and bighorn sheep. Connectivity at this continental scale is critical to maintaining ecosystem processes, biodiversity, wildlife movement, and habitat values of existing conservation investments in both countries.
This study was undertaken as part of a larger effort to conserve the integrity of this landscape linkage, in the face of increasing sprawl of development inland from the coast, escalating border security infrastructure, and other competing uses for the land. It focuses on the border region of California and Baja California, where the long-term connectivity between federally endangered bighorn sheep in Peninsular Ranges of Southern California and bighorn sheep in Baja California is threatened. The current level of connectivity and the possibilities for maintaining this connectivity in the future are not well understood. This preliminary study assesses the distribution and habitats of bighorn sheep in the Sierra Juárez in Baja California, just south of the international border, the potential threats to bighorn sheep there, and the threats to this landscape linkage, so as to inform conservation and management strategies for linking protected parklands in both countries.
