The experience intensified her creeping sense that tortoises were becoming scarcer. Berry joined fellow desert lovers in badgering the Bureau of Land Management to designate a safe haven for the animals on roughly 40 square miles between China Lake and Edwards Air Force Base. Stebbins and Leopold were enlisted as heavyweight names in their letter-writing campaign. Once the BLM agreed in 1973 to the creation of what became the Desert Tortoise Natural Area, Berry says a staffer wearily asked her, "Would you get your friends to stop writing now?"

The following year, the BLM's California Desert District Office hired its pesterer. The dainty, exacting Berry was one of the first women to infiltrate the cowboy culture of field offices. She piled boxes on the extra chair in her office so colleagues wouldn't plop down and socialize while she was working. In one of her first projects, she helped draft multiple-use plans for California's roughly 22-million-acre chunk of the Mojave.

Berry knew that the tortoise was threatened by an ever-expanding network of military bases, with a collective footprint already larger than the state of Connecticut, as well as by more than 30,000 miles of transmission lines, pipeline and roads. But setting aside land for tortoises required understanding exactly where they lived. "We didn't know about their distribution," she says.

She began organizing dozens of long-term study plots, where researchers walked mile after mile in search of burrow entrances underneath ancient creosote. Tortoises were periodically caught, marked and recaptured. Elsewhere, she laid out more than 1,500 transects, and over the years, Berry and more than 100 young fieldworkers she's trained have repeatedly patrolled them, looking for live animals, carcasses, scat and burrows. "I was thinking ahead," she says, collecting long-term evidence.

In 1980, a stunning update came from state biologists in Utah: The Beaver Dam Slope colony Woodbury and Hardy once studied had crashed, from 300 to just 82 animals. In response, the population was listed as "threatened" under the federal Endangered Species Act.

Four years later, Berry published an 848-page report showing Mojave-wide declines that made Beaver Dam Slope look mild. The population had dropped as much as 90 percent in the last century, from historic densities of perhaps 150 tortoises per square kilometer. It was less a question of "whodunit" than "what hadn't." Cattle competed for grass and spread invasive weeds. Dune buggies and motorbikes destroyed forage and entombed tortoises in their own burrows. Highways divided historic territories, and some people used tortoises for target practice. In drought years, coyotes devoured them, and the ravens that followed humans and landfills into the desert ate the soft-shelled young and eviscerated adults.

The animals were disappearing faster than they could reproduce. Like humans, tortoises can live 50 to 80 years and don't procreate until their teens. But only about 2 percent of their offspring survive to maturity in the wild.

Defenders of Wildlife, the Natural Resources Defense Council and Environmental Defense Fund petitioned the U.S. Fish and Wildlife Service to list the entire Mojave population. The agency agreed that listing was warranted but said other, higher priorities precluded it.

In 1988, a graduate student working at the Desert Tortoise Natural Area noticed that many of the animals were sick and dying. "They appeared to be dehydrated with sunken eyes," Berry says. "They had dried snot on their front legs where they would rub their nose and eyes. Some were emaciated and limp and had muscle wasting."

Berry's team surveyed the site and found staggering losses: More than 600 carcasses, and 43 percent of the living animals showed symptoms. Again, environmental groups petitioned Fish and Wildlife to list the entire Mojave desert tortoise population. This time it responded, issuing an emergency "endangered" order in 1989.

Pathologists were flown in to euthanize and autopsy sick tortoises, and reports of illness in other colonies came in. They discovered that the reptiles were afflicted by an upper respiratory tract disease caused by a novel strain of Mycoplasma, the bacteria associated with human "walking pneumonia." Outbreaks in wild populations near cities convinced Berry and others that it had been introduced by the surreptitious dumping of sick pet tortoises.

But the disease hit Kern County hardest; the tortoise was not at risk of extinction throughout the rest of its range. So, in 1990, its status was reduced to "threatened."

Berry became one of the chief contributors to a recovery plan striving for the highest possible conservation values, and 6.4 million acres of critical habitat were designated. The plan divided tortoises into six evolutionarily distinct groups in a way that anticipated by almost 20 years their eventual splitting into two species -- Gopherus agassizii to the west of the Colorado River, and the Sonoran's more hill-dwelling Gopherus morafkai to the east. Recovery efforts for each group would be tailored to local conditions. Though the 1994 plan was widely applauded by environmentalists, it was promptly lost in bureaucratic red tape.

When, a decade later, Fish and Wildlife hired Averill-Murray to rewrite it, Berry was left out of his team's inner circle. She had moved to the U.S. Geological Survey in 1993, but continued her tortoise work. Not only did she distrust translocation in general, she was also convinced that translocating captive tortoises could seed new epidemics like the one that sparked the listing in the first place.

But development was exploding in the southern Nevada desert, and Averill-Murray's team had only two options. A study in The Journal of Wildlife Management sums up the dilemma they faced: "The conservation of habitat should always take precedence for conservation planning, but when habitat is lost because of political or economical decisions, only 2 choices remain: 1) leave animals in harm's way to die … or 2) collect the animals assuming that they may be useful for conservation in the future."

Averill-Murray chose Door #2. Tortoises were not stopping the industrialization of the Mojave, so his team created a plan that would concentrate management under a Reno-based office that would lead translocation efforts, and adjust recovery actions based on changing climate and other factors.

To increase the survival rate for translocated tortoises, his group wanted to experiment with captive animals. Although 3,000 had  been euthanized at a holding facility because they'd been exposed to Mycoplasma, his group was increasingly convinced that the disease was not chronic, like tuberculosis, but rather more like a passing cold. As they saw it, there was no time to waste in the increasingly desperate quest to improve translocation protocols.