Judge Rejects Federal Project Threatening California’s Desert Tortoises

A judge has rejected federal agencies' approval of activities in the California Desert Conservation Area, including a vast network of off-road vehicle routes in the West Mojave Desert. The activities are driving desert tortoises and other threatened and endangered wildlife toward extinction.

"Yesterday's court decision is the culmination of our 18-year legal battle to adequately protect the threatened desert tortoise and its critical habitat from off-highway vehicle use on public lands in the western Mojave Desert," said Jeff Aardahl, senior California representative for Defenders of Wildlife. "This is clearly a win for the desert tortoise, which has been on a path toward extinction for decades."

"I'm grateful the court found that federal officials can't just make empty promises to protect desert tortoises and other wildlife on our public lands from off-road vehicles," said Lisa Belenky, an attorney at the Center for Biological Diversity. "The Western Mojave's desert tortoises are sliding toward extinction, so it's long past time for the Bureau of Land Management to curb these vehicles' threats to the tortoises and all the rare plants and animals in California's beautiful deserts."

Tuesday's ruling is a victory for conservationists. In 2021 environmental groups sued the Interior Department, Bureau of Land Management and Fish and Wildlife Service over the 2019 West Mojave Route Network Project, which failed to minimize off-road vehicles' harms to public lands and protect endangered and threatened species and their habitats.

"This ruling makes clear that the BLM hasn't done nearly enough to minimize impacts from off road vehicles in the West Mojave," said Tom Budlong of the Sierra Club. "The BLM's empty promises and Fish and Wildlife Service's failure to use the best available science have allowed increasing degradation of our public lands and pushed the desert tortoise closer to extinction."

U.S. District Judge Susan Illston ruled that the Bureau violated the Federal Land Policy and Management Act by designating off-road vehicle routes without basing its criteria on minimizing damage to resources. That includes habitat for species such as the endangered Lane Mountain milk vetch, which is found only in the western Mojave Desert.

"The court got it right in finding that the Fish and Wildlife Service's biological opinion ignored the best available science that shows the need to proactively protect rapidly declining desert tortoise populations and habitats in the Western Mojave Desert," said Ed LaRue of the Desert Tortoise Council. "The Bureau cannot continue to prioritize recreational vehicle opportunities in fragile desert tortoise habitats over the species' survival."

The judge also ruled that the Bureau wrongly assumed that there would be no growth in off-road vehicle activity or harm to air quality from the new routes.

Under the West Mojave plan, the BLM adopted nearly 6,000 miles of dirt roads for off-road vehicle use (that's enough to go approximately one-quarter of the way around the Earth's circumference). This has led off-roaders to create hundreds of new illegal roads in fragile habitat that is supposed to be protected for desert tortoises. The desert tortoise population has now declined to unsustainable levels in the western Mojave Desert.

"The Mojave Desert is one of North America's largest remaining areas of connected habitat, and the BLM's management decisions have consequences," said Nick Jensen, conservation program director at the California Native Plant Society. "Today's ruling is a reminder that we must do more to protect sensitive ecosystems and imperiled species, like the Lane Mountain milk vetch."

The court also invalidated the Fish and Wildlife Service's biological opinion, ruling that the agency violated the Endangered Species Act by ignoring studies showing threats to the desert tortoise and harm from off-road vehicles and by relying on unenforceable mitigation measures. The judge also said the Fish and Wildlife Service used an irrational "surrogate" approach to determine the number of desert tortoises that would be killed or taken and failed to require enforceable measures to minimize harm to the animals. The Bureau violated the Act by relying on the Fish and Wildlife Service's flawed analysis, the judge ruled.

The groups are represented by the Stanford Law Clinic and the Center for Biological Diversity.