The terrain encompasses overlapping biological zones that provide habitat for mountain lions, the California desert tortoise, bighorn sheep, fringe-toed lizards and more than 250 species of birds.
Two bills introduced by Feinstein over the past six years languished in Congress amid conflicts among off-roaders, hunters, environmentalists, and mining and renewable-energy interests. Unable to gain momentum on her California Desert Conservation and Recreation Act again this year, Feinstein decided to ask Obama to act unilaterally by invoking the Antiquities Act to create the monuments.
"Despite strong support from the many stakeholders in the desert, from conservation groups, off-road recreation supporters, counties, energy companies, water districts, business groups and tribes, we have not been able to move it in the Senate, and the House has yet to introduce the version I'm told they've been working on for months," Feinstein told The Times on Friday.
The California Democrat asked Obama in a letter Aug. 3 to designate monuments known as Mojave Trails, Sand to Snow and Castle Mountains. Doing so would ensure the protection of their natural and cultural resources and recreational and economic opportunities, she said.
In a statement Friday, Feinstein said she has not given up on winning congressional approval. Her request, which the senator acknowledged after The Times obtained a copy of her letter to Obama, applies pressure on Congress and the various interest groups to resolve their differences or face presidential action in which they have little voice.
Presidents dating back to Theodore Roosevelt have used the 1906 Antiquities Act to protect "objects of historic or scientific interest." Critics say the act has been abused by presidents of both parties to unreasonably deny the public the right to use the land in a multitude of ways.
Feinstein was encouraged to seek presidential action by conservation groups including The Wildlands Conservancy, the Sierra Club, Defenders of Wildlife, the Center for Biological Diversity, the Mojave Desert Lands Trust and Friends of the Desert Mountains.
The Obama administration did not respond to inquiries about Feinstein's request.
The proposed monuments are quite distinct from one another.
Mojave Trails National Monument would encompass 921,000 acres of federal land and former railroad property along a 105-mile stretch of old Route 66, between Ludlow and Needles, and protect wildlife corridors linking Joshua Tree National Park and the Mojave National Preserve.
Sand to Snow National Monument, about 45 miles east of Riverside, would embrace about 135,000 acres of federal land between Joshua Tree National Park and the San Bernardino National Forest in San Bernardino and Riverside counties. The area includes roughly 24 miles of the Pacific Crest Trail and Big Morongo Canyon, a birding hot spot that was designated a federal Area of Critical Environmental Concern in 1982.
Castle Mountains National Monument would include a desert outback left out of the 1994 California Desert Protection Act due to an active gold mine that ceased operations in 2001. Located near the Mojave National Preserve, the area includes the historic mining town of Hart.
Much of the land under consideration was purchased more than a decade ago by private citizens and conservation organizations, then donated to the U.S. Bureau of Land Management in anticipation that they would eventually come under protection of national monument status.
"We're among the California desert lovers who raised the funds to buy a big chunk of these lands," said David Myers, executive director of The Wildlands Conservancy. "So hats off to Senator Feinstein for trying to honor commitments that are now decades old."
Feinstein's request comes nearly a year after Obama designated much of the Angeles National Forest as the San Gabriel Mountains National Monument. That action came with no government funding.
Amy Granat, managing director of the California Off-Road Vehicle Association, was disappointed with Feinstein's action. "We believe the use of the Antiquities Act to designate any national monument is an overreach of executive authority," she said.
San Bernardino County Supervisor James Ramos, whose district includes much of the land targeted for monument status, expressed mixed feelings about Feinstein's request.
"We want this bill to proceed through the legislative process," Ramos said. "But if the administration moves forward with an executive action, we strongly support protection of existing mining rights in those areas."
Either way, he added, "the new national monuments could transform the California desert into a destination for the entire nation, if not the world."