Almost a quarter century has passed since the Mojave desert tortoise was first listed. Nineteen years have gone by since Berry co-authored a recovery plan that, if implemented, might well have succeeded by now, say conservation groups. That 1994 plan sought to return tortoise numbers to where they were before Mycoplasma hit. The new plan seems less ambitious, with a goal of reaching the numbers found in 2001, when Fish and Wildlife began its own range-wide monitoring.

Both the original and revised plans were filled with suggestions about what should be done to recover the tortoise in addition to translocation. Over the years, federal agencies have spent millions to acquire land, install protective fences, retire grazing allotments, limit off-roading, cover landfills and close trails.

Some pieces of the 6.4 million acres of BLM land designated as critical habitat in 1994 have changed jurisdiction since then, including millions of acres transferred to the National Park Service. Most critical habitat remaining under BLM management now has special protection as "areas of critical environmental concern" or "desert wildlife management areas"; in the latter, development is limited to 1 percent of the total area. The USGS and FWS are working with energy planners to retain wildlife corridors between critical habitat areas. And yet, according to a 2012 study in BioScience by Averill-Murray and others, the "effectiveness of most recovery actions is … unknown," and in many parts of its range, the tortoise continues to decline.

"If we don't get serious about taking away some of the stressors on tortoises," says Anderson of the Center for Biological Diversity, "they may go extinct. We need habitat where the highest priority is desert tortoise conservation and where we can remove the other threats." She ticks off the big national parks, none of which are really prime tortoise territory: Death Valley is too low and too hot, while Joshua Tree's most suitable habitat is too accessible to humans, and the Mojave National Preserve allows grazing. The animal's best hope, she says, can be seen at the Desert Tortoise Natural Area that Berry helped found. It's fenced off and entirely dedicated to tortoises; other uses are excluded, including off-road vehicles. "Data from there show tortoise densities much higher than in critical habitat managed by the BLM next door," she says, citing research being done by Berry and others. "(Their) study will provide a compass on how to manage for tortoises."

And Fort Irwin, perhaps, provides a "how not to" for tortoise management. Five years after the 158 healthy tortoises tagged for Berry's study were moved, she says, "84 are dead. Another 21 are missing. Six or seven of those, we're sure they're dead. We found chewed-up transmitters."

She will track the survivors through the bleak hills near Barstow to get a long-term picture of their survival rate. For such long-lived animals, five years of living after being uprooted might still end in slow starvation, or they might genuinely be re-establishing themselves. "We still don't know if translocation works," Berry says. "We need long-term studies. We need numbers."

Even if translocation techniques are improved, she firmly believes that the best thing that can be done for the desert tortoise is to leave it alone. And in the most protected areas, that might happen. But elsewhere across a 48,000-square-mile desert, it seems inevitable that tortoise-moving will continue. For Berry, every inch a product of the late-'60s ecology movement, it's intolerable to contemplate that the animal she's devoted her life to might become dependent on the kindness of rangers.

Berry continues gathering data from her plots and transects across the Mojave and part of the Sonoran deserts. By the time she retires, says her boss, Steve Schwarzbach, her life's work will appear in what he calls her "masterpiece": the longest, most extensive survey of the animal's demographics and survival rates ever done, and a mighty study of the tortoise's passage into the Anthropocene. His provisional title for it: "The 40-year decline of the desert tortoise."

Yet when Berry is asked if she gets depressed chronicling the disappearance of an animal older than recorded history, she seems surprised. Then, in her flat, matter-of-fact way, she replies, "People like myself, the best we can do is present the best possible science and be an advocate for its use. I don't allow myself to get depressed because it takes up time -- and I don't have that much left."

Award-winning reporter Emily Green is an environmental writer based in Los Angeles. She blogs about Western water at www.chanceofrain.com.

This story was funded with reader donations to the High Country News Research Fund.