The study also determined where the big cats live. Their densest populations are in coastal forests in Humboldt and Mendocino counties, while they’re least dense in the high desert east of the Sierra Nevadas in Inyo County. “The Central Valley and portions of the Mojave Desert have no mountain lions,” Dellinger told the Times. Mountain lions are under consideration for threatened status. The California Fish and Game Commission is expected to rule on the issue later this year.