Roy Averill-Murray resembles a thinner Kevin Costner with a less-pronounced chin, wearing sunglasses and with a tortoise embroidered on his baseball cap. The most controversial figure in desert biology, he radiates an affability that earns the deep affection of his field workers. Whenever they come in from the desert, he has a cooler of beer waiting. He did his master's thesis on the tortoise at the University of Arizona, and worked for the state's Game and Fish Department as desert tortoise coordinator before joining the federal agency. "I've been working on tortoises for 22 years," he says. "I turned 45 this year and realized it was getting to the point that it has been close to half my life."

Just as Averill-Murray started his new job, trouble erupted over a habitat conservation plan arranged in 1990 between Clark County, Nev., and federal regulators. Under that plan, developers had agreed to build and donate a 222-acre tortoise holding facility, the Desert Tortoise Conservation Center, in south Las Vegas. For every acre of tortoise habitat lost to houses, a fee would be paid toward the running of the place, which would take in displaced wild tortoises. These animals would then be translocated, donated for lab experiments or, if diseased, humanely dispatched.

From 1990 through 2005, habitat conservation plans mimicking the Vegas model were written to cover millions of acres across Nevada and California. The parcels making up the 6.4 million acres of critical habitat became ever more isolated from one another by industrialization. In 2005, a wave of military expansions and solar and wind farms began to hit the Mojave. Of many mitigation schemes stipulated by these habitat conservation plans, from covering landfills and sewage ponds to restricting off-road vehicle use, one of the most common required purchasing mitigation land for displaced tortoises.

That soon revealed more problems with translocation schemes. There just isn't that much good unoccupied desert left, for one. "The habitat is basically full," says Berry, and in places where native populations have declined, it doesn't make sense to release more tortoises until you know why the original residents died out. Also, unless a mitigation area is protected, the animals might eventually get moved again.

Back in southern Nevada, the very facility created by the original habitat conservation model was falling apart. It had looked good on paper -- until the center began filling up, not just with displaced wild tortoises, but also surrendered pets, either captured before the species was listed or the offspring of such captives. "It's ironic that it's a threatened species and that they do so well in captivity and that creates this overabundance," says Averill-Murray. "They started piling up and piling up and piling up."

Overcrowding got so bad that, starting in 1995, more than 9,000 tortoises were released on BLM land near Jean, Nev. Nobody knows how many survived. "If you go out there today, there are a lot of dead tortoises," says Averill-Murray.

In 2010, Clark County stopped funding the Desert Tortoise Conservation Center, saying it was no longer fulfilling its original purpose. Averill-Murray doesn't blame the county. "They were spending over a million per year just dealing with pet tortoises. That's funding that wasn't going to conservation or recovery," he says. Since that time, the center has struggled to survive and is scheduled to close in 2014.

By 2011, turtle-moving was making national news. The Fish and Wildlife Service gave BrightSource Energy permission to displace roughly three dozen adult tortoises for its planned 3,500-acre Ivanpah Valley solar complex on the California-Nevada border, spurred by a federal goal stating that by 2015 plans must be in place for "renewable energy projects located on the public lands with a generation capacity of at least 10,000 megawatts of electricity."

But as tortoise after tortoise was unearthed in Ivanpah Valley, it became apparent that there were many more than originally thought -- perhaps 1,000 animals, if hatchlings and juveniles were included. After an attempt in court by the Western Watersheds Project to halt construction failed, BrightSource CEO John Woolard insisted he was actually saving turtles, telling the House Oversight Committee in 2012, "We expect to return more desert tortoises to the wild than were captured on site, as we have had over 50 new hatchling tortoises born in captivity at Ivanpah in the temporary pens last fall."

Amid the emerging chaos in Ivanpah, in March 2011, biologists poured into Las Vegas for the long-awaited revision of the recovery plan. "Everyone in the environmental community felt like this is the big unveiling moment," says Ileene Anderson, the Center for Biological Diversity's desert specialist. But it turned out that the plan was missing a crucial component. "There was this roomful, 70 or 80 people there, and then they say they didn't have time to do a renewable energy chapter, so they would add that later. It was bizarre."

"When we started the revision process (in 2004) all this renewable energy wasn't on the radar," explains Averill-Murray, "so we really didn't address those issues head on … It would have taken a wholesale change at the eleventh hour." He expects the chapter on renewable energy impacts to come out of review by the end of this year.

Once it does, given the political push toward renewable energy, Fish and Wildlife is unlikely to stymie future solar or wind power projects. But some things may be changing. "To industry's credit," says Anderson, "at least the solar folks learned their lesson with Ivanpah. They're now trying to do due diligence and select places they know have fewer tortoises." Massive solar projects are even being sited on former agricultural land instead of pristine desert.

Nonetheless, just under 52,000 acres of federal land in the Southwest, much of it tortoise habitat, have been approved for solar projects, according to BLM energy liaison Ray Brady. On top of 37 renewable energy projects licensed since 2009, the BLM is considering 20 more proposals, 14 for solar and six for wind. The agency's final environmental impact statement for solar energy zones in tortoise territory in Arizona, Nevada, Utah and California, asserts that, "Despite some risk of mortality or decreased fitness of the desert tortoise, translocation is widely accepted as a useful strategy for the conservation of this species." As evidence, it repeatedly cites a 2007 paper by Averill-Murray's team that tracked just 32 translocated animals for two years, during which a fifth of the tortoises died.

Averill-Murray's team is now working with biologists from the San Diego Zoo to use the Desert Tortoise Conservation Center's 2,000 or so captive tortoises, some of which have been exposed to Mycoplasma, in translocation experiments. Averill-Murray recognizes the risk of spreading illness to wild populations, but says, "Disease is a normal fact of life. It's unrealistic to expect that there's going to be a pure wild population out there that we're somehow going to contaminate."

Since the 1971 dumping of turtles on China Lake, translocation methods have steadily improved. Animals now must be released early in the morning and in spring, when forage and water are more available. Averill-Murray's group wants to refine the process further. So they've been experimenting to see how juveniles, which are more vulnerable to predators but theoretically less bonded to a previous habitat, do in an ongoing translocation of young turtles to the Nevada Test Site. In another experiment, they're releasing tortoises in more sheltered washes instead of in open basins, which had been widely done in the past, and rather than dipping them in a hydrating bath before release, they're injecting them with saline solution.

On the last day of April, as Averill-Murray and the San Diego Zoo team prepared 32 tortoises from the Center, a young post-doc named Jen Germano used ultrasound on female translocatees to see if they were carrying eggs. They hope the released animals will produce hatchlings to repopulate Trout Canyon, a Joshua tree-studded crease in the Pahrump Valley where once-plentiful tortoises have become scarce. Researchers in a shade tent use putty to attach radio transmitters to shells for tracking. The animals are so tame that they don't withdraw into their shells when handled. That's a defense they will quickly rediscover, says Germano: "They learn pretty fast how to be tortoises again."

The day after the animals are tested for disease and tagged, Averill-Murray's team meets at dawn and loads them up: 16 outwardly healthy but Mycoplasma-positive tortoises and 16 that have tested negative. If, as he suspects, positive antibody status is nothing more than evidence of a tortoise with a well-educated immune system and the Kern County tortoises so badly hit by Mycoplasma in 1988 were uniquely vulnerable, then that frees up a lot of experimental animals for future use.

At Trout Canyon, they're removed from the straw nests in their traveling cases, injected with saline and carried to selected locations in sheltered washes. Field staffers are visibly moved as they set the captives free. "Look at you in your new home," one biologist murmurs to GT3125, a female perhaps 20 years old.

A raven circles overhead as the tortoises begin to explore their surroundings. As the scientists depart, a civilian truck carrying a bright red dune buggy waits to drive up the dirt road towards where the tortoises are tasting their first, and possibly last, wildflowers. The tortoises will be monitored for the next five years, says Averill-Murray, provided that they survive and that funds for such monitoring last.