On August 3, 2015, Sen. Dianne Feinstein wrote a letter to President Obama urging him to designate Mojave Trails, Sand to Snow, and Castle Mountains as national monuments. The three areas constitute more than one million acres in Southern California deserts, woodlands, mountains, and historical sites. The designations, which would require no congressional approval, would protect habitat important to desert tortoises, bighorn sheep and golden eagles, while preserving portions of historic Route 66, the Pacific Crest Trail and the headwaters of Southern California's longest river, the Santa Ana.
Congress has failed to act on Sen. Feinstein’s "California Desert Conservation and Recreation Act," a bill introduced in February 2015 to protect 1.4 million acres in Southern California, while offering permanent access for off-highway vehicle riders and promoting renewable energy development. Feinstein's request comes as the White House is ramping up its use of the 1906 law called the “Antiquities Act” to permanently set aside public lands from mineral development. The controversial law has raised the ire of Republican leaders who say it gives the executive branch unchecked powers, and has been abused by presidents of both parties.