1999 – The Center filed a notice of intent to sue over the gigantic Cima Cinder Mine, which destroyed large portions of desert tortoise critical habitat and annually stripped away 7,500 tons of cinder from a supposedly protected cinder cone within the Cinder Cones National Landmark. In the same year the Center, the Sierra Club, and Public Employees for Environmental Responsibility brought about the closure of the Bureau of Land Management's 339,553-acre portion of the Lanfair Valley grazing allotment, which lay within critical habitat for the desert tortoise.
March 2000 – Public pressure and a Center threat to sue led to the permanent cancellation of livestock grazing on the 276,125-acre Granite Mountains allotment, which lies within the Bristol Mountains Wilderness, the Mojave National Preserve, and the University of California's Granite Mountains Natural Reserve.
March 2000 – The Center, Sierra Club, and Public Employees for Environmental filed suit against the Bureau of Land Management and the Fish and Wildlife Service on behalf of 24 endangered species that had been hurt by poor land management on the California Desert Conservation Area.
2000-2001 – Due to a series of sweeping settlements stemming from the Center's March 2001 landmark lawsuit, millions of California Desert Conservation Area acres were protected from destructive human impacts. The Bureau of Land Management promised to prohibit mining on 3.4 million acres, reduce or prohibit livestock grazing on 2 million acres, prohibit off-road vehicles on a total of more than 550,000 acres, close more than 4,500 miles of roads, and increase wildlife surveying, monitoring, and conservation plans. The agency also agreed to protect the Peninsular bighorn sheep and its habitat, close a sand and gravel mine threatening the arroyo southwestern toad, require the use of wildlife-safe engine coolant and make power lines raptor-proof.
September 1, 2001 – In a move to help protect the desert tortoise, the Bureau of Land Management put into immediate effect grazing-restriction decisions arrived at through a settlement with the Center.
May 30, 2002 – It was announced that the Western Mining Action Project — on behalf of the Center, Citizens for Mojave National Park, and the National Parks Conservation Association — filed a protest with the Bureau against patent mining claims and millsites to mining company Viceroy Gold.
June 20, 2002 – The Center, Public Employees for Environmental Responsibility, Citizens for Mojave National Park, and the Desert Tortoise Council petitioned the Secretary of the Interior to govern hunting in the Mojave National Preserve of California.
June 20, 2003 – The Center and allies filed suit to challenge the West Mojave Off-Road Vehicle Designation Project, a plan that would allow off-road vehicles on up to 1,000 miles of new roads across 3.2 million acres of desert tortoise and other wildlife habitat in the Mojave Desert.
July 7, 2003 – The Center and 11 other conservation groups filed suit over a federal plan to open more than 49,000 acres of endangered species habitat on the Algodones Dunes to intensive off-road vehicle use.
March 1, 2005 – To protect native Mojave Desert wildlife, the Center and Public Employees for Environmental Responsibility filed suit to stop the installation of artificial water systems in California's Mojave National Preserve.
March 17, 2005 – The Center called on off-road vehicle racing promoters and California City officials to halt an unpermitted off-road race within important habitat for the desert tortoise, Mojave ground squirrel, Barstow wooly sunflower, and other sensitive California desert species.
April 6, 2005 – In response to the Center's March 1 suit, the National Park Service abruptly blocked installation of wildlife-harming artificial water systems in California's Mojave National Preserve.
March 14, 2006 – Concluding the July 2003 case brought by the Center and allies against the Algodones Dunes Plan — a management plan backed by the off-road vehicle lobby that would threatening the Dunes and their inhabitants — the court ruled to uphold protections for the area. The court also found that the U.S. Fish and Wildlife Service had violated the Endangered Species Act in excluding almost 60 percent of Peirson's milk vetch habitat from the dune native's critical habitat designation.
August 14, 2006 – The Center and a broad coalition of other conservation groups, public employees, and rural property owners challenged the Bush administration in federal court for failing to protect private property, conservation lands, and endangered wildlife from off-road vehicles across 7.1 million acres of the California Desert Conservation Area in Imperial, Riverside, San Bernardino, Los Angeles, Kern, and Inyo counties.
November 8, 2006 – The Center, the National Parks Conservation Association, and other conservation groups sought to intervene in a federal lawsuit seeking to allow extreme off-road vehicle use in a fragile desert stream in Death Valley National Park's Surprise Canyon. Off-road groups' attempt to gain access to the stream relied on a Civil War-era law, now repealed, called R.S. 2477.
January 18, 2007 – The Center and a coalition of other environmental groups filed legal papers to intervene in a federal lawsuit by Inyo County that would let bulldozers cut new highways through Greenwater Canyon, Greenwater Valley, and Last Chance Canyon in Death Valley National Park. The planned bulldozing was an attempt by off-roaders, counties, and states to take over little-used tracks on federal lands on the basis of the outdated law R.S. 2477. A federal judge later ruled that we must be included in the lawsuit.
July 25, 2007 – Ruling in the Center's November 2006 lawsuit, a federal court denied an attempt by off-road vehicle enthusiasts to reopen Surprise Canyon to extreme off-road vehicle use.
September 18, 2007 – A judge denied off-road vehicle interests' second attempt in a year to gain access to the fragile Surprise Canyon.
October 24, 2007 – A judge ruled that the Center and allies must be included in a lawsuit that would let San Bernardino County turn small rural roads on the Mojave National Preserve into freeways. The county was attempting to gain control over 14 roads within the preserve using R.S. 2477.
October 27, 2007 – A federal judge ruled that we must be included in the Inyo County lawsuit in which we sought to intervene in January 2007.
July 2, 2008 – The Center and Desert Survivors filed suit in federal court against two government agencies over the relocation of hundreds of desert tortoises and the transfer of land-management authority from the Army to the Bureau of Land Management without required environmental review.
August 12, 2008 – Inyo County's highway-building lawsuit was largely thrown out by a federal judge, who dismissed the county's claims to all of one route and most of the other two routes.
October 9, 2008 – In response to the July lawsuit brought by the Center and Desert Survivors, Fort Irwin officials suspended their disastrous desert tortoise translocation program — unfortunately, not before the project caused huge tortoise losses.
December 18, 2008 – The Center filed suit challenging the Bureau of Land Management's Coachella Valley amendment of the California Desert Conservation Area Plan, which would allow Dunn Road — an illegally constructed roadway in Peninsular bighorn critical habitat — to be opened to commercial vehicular use.
January 2009 – The Center filed suit against the Bush administration over its 2007 reduction of critical habitat for the Peirson's milk vetch.
October 7, 2009 – The Center and allies filed a notice of intent to sue the Fish and Wildlife Service for reducing critical habitat for the endangered Peninsular bighorn sheep by 55 percent — much of the habitat in question lying within the California Desert Conservation Area.