Louis Sahagun / Los Angeles TImes

President Obama's proclamation of a new national monument he designated in California's Mojave Desert has rockhounds worried they are no longer welcome on public lands with a reputation for prime gem and mineral specimens.

The proclamation ensures public access for utilities, cattle ranching, hiking, camping, backpacking, hunting, fishing, rock climbing, bicycling, bird watching and other outdoor recreational activities in Mojave Trails National Monument, which encompasses 1.6 million acres of federal land along a 105-mile stretch of old Route 66 between Ludlow and Needles.

The one thing visitors apparently can't do in mineral hot spots, including Afton Canyon, the Cady Mountains and Lavic, is take a rock a home.