Although I fear and despise nearly all rodents, I was smitten with this one. I longed to see a live one, bounding on across its native land. Photograph by Loomis Dean/The LIFE Picture Collection/Getty

The first giant kangaroo rat I saw was fluffy and round, with cartoonishly large eyes. It looked like something that might be big in Japan. It was also long dead—stuffed, mounted, and stuck haphazardly alongside a dozen other, less exotic mammals (a skunk, a possum, a field mouse) in a low display case on the uppermost floor of the Natural History Museum of Los Angeles. Although I fear and despise nearly all rodents, I was smitten with this one. I stared at the fuzzy ball, the elongated feet, posed as if primed for a leap. And, as I stared, I longed to see a live one, bounding on across its native land. This was, it so happened, not too far away from where I stood.

The Carrizo Plain is four hours north of Los Angeles by car—three, if you start ignoring the speed limit as the population dwindles and the sky and land open up over the southern half of California’s great central valley, the San Joaquin. The single road that runs through the plain goes from busted asphalt to gravel to dirt and back, slicing through its middle, southeast to northwest, some forty miles. The plain is bounded by two mountain ranges, the Temblor, which is to the northeast, and the Caliente, which is to the southwest, and is cleaved by a ridged gash in the earth—the San Andreas Fault. It is here, in the desolate Carrizo, that the fault is often photographed, and it is those pictures that often end up in geology textbooks. Giant kangaroo rats do live elsewhere, in ever-dwindling pockets of the San Joaquin, but mostly they are here, in the windswept wild grasslands of the plain.

One afternoon last autumn, I arrived at an old ranch house, where I met Scott Butterfield, a senior scientist at the Nature Conservancy. The conservancy owns the ranch and co-manages the plain, along with the U.S. Bureau of Land Management and the California Department of Fish and Wildlife. Butterfield previously worked on a project that used satellite imagery to track kangaroo-rat populations. The animals are solitary grazers, meticulous and territorial. Around their earthen burrows they create mowed lawns like crop circles, leaving clippings and seeds out to bake in the sun before storing them for later feasting. This zone of grazing and burrowing is called a precinct, and the precinct of a single kangaroo rat is typically large and distinct enough to spot from space.

In a good year, that is; 2014 was not a good year. The drought had reached historic, potentially catastrophic proportions, and the rats’ numbers were way, way down. Butterfield had worked on the plain for nearly eight years, and this was the worst he had seen it. Still, they were out there, he said, if I was willing to look and possibly not find anything. (“Carrizo is an acquired taste,” he told me.) By that time of year, the giant-kangaroo-rat researchers had mostly packed it in and headed back to their campuses. But Bob Stafford, an environmental scientist and acquaintance of Butterfield’s, was still running spotlight surveys for kit foxes. These surveys consisted of long drives across the plain and back in the middle of the night. It was as good a chance as any of spotting a rat. So, at 10 P.M., we joined him.

Like the giant kangaroo rat, kit foxes are endemic to the California grasslands, which means that their final significant wilderness holdout is also in the Carrizo. Stafford has been “on the plain” for sixteen years. Before that, he studied bears in the Sierra Nevada and kit foxes in the San Joaquin. His knowledge of the plain is vast, and as we drove southeast from the ranch into the dark, he pointed at the silhouettes of distant peaks. Up in the swales, below the ridges to the west, Stafford said, were spadefoot toads and fairy shrimps—like sea monkeys, but endangered—which appeared in the vernal pools if and when the rains came. Now that the nights were getting crisp, the tarantulas were starting to come out to look for mates. We slowed near an abandoned farmhouse favored by pallid bats, which scoop the tarantulas and scorpions and Jerusalem crickets up off the ground and eat them, discarding the legs and tails.* We saw a lone tarantula by the roadside, stopped and waggling its front legs slowly and methodically, a robot waving hello. “This is where we saw the mountain lion,” Stafford said, pointing to a hill close to the road. The foxes stay away from the “steep stuff,” he said, because that’s where they get eaten.

Stafford and Butterfield manned the two spotlights, one on either side of the four-door pickup, and I sat behind them with a spreadsheet that Stafford had given me, which listed many unfamiliar names. I pointed to one. “ ‘Tata’?” I asked. “It’s not that complicated,” Stafford said. “ ‘Tata’ is Taxidea taxus: badger.” We probably wouldn’t be seeing any of those. And, indeed, it was Lepus, Lepus, Sylvilagus, Lepus—jackrabbit, jackrabbit, cottontail, jackrabbit—for nearly the whole drive, single side eyes glimmering in the light. Then a fox, trotting across the plain and stopping to regard us casually before trotting away again through the darkness. Stafford said that, even though young coyotes are fox-sized, the foxes are unmistakable. Their gait is jaunty, tails straight out, and they are more curious than coyotes, which usually run from a spotlight. Plus, young coyotes just look doofy, there was no other way to put it.

We fell into silence, the hum of the motor and rattle of the road, a rhythmic sweep of the spotlights across the barren land. I asked the two biologists whether either had ever come out on the plain at night and seen no animals at all. Stafford had only once, after a big rain, when the grass came in so high and thick that a critter would’ve had to jump into his passenger seat for him to see it. The efficient mowings of the giant kangaroo rats are crucial in such times. So many of the plains creatures rely on open space, including the pronghorn antelope, which had been reintroduced to the area decades earlier and was barely hanging on. The rats are crucial in the dry years, too. Their tendency to store food means that they survive lean times longer than most. They are a keystone species, providing food for the foxes and coyotes and shelter for others: many ground dwellers make homes out of the rats’ burrows, which pockmark the plain.

Stafford said that he had seen droughts on the plain before, back in the eighties, but this was worse. There wasn’t a rat in sight. Most years, typical years, they’d be hopping around like crazy, outnumbering everything else we could spot. But what was typical anymore? It was getting so bad that there was talk of supplementing the rats’ food with air drops. “We talked about this in the eighties, too,” Stafford said. “I think we’re past that point now,” Butterfield said. “It’s just too wild to think about—it’s such a drastic measure, and they’re covering hundreds of thousands of acres. How would it even work?” The drought was turning this semi-arid grassland into a desert. Only if the rains came would the rats and the grass rebound. The question wasn’t whether the animals were capable of it but whether the Carrizo Plain was still a place where such transformations could and would occur.

As we approached the southern end of the plain, a bobcat stepped into our headlights. It glanced back at us quickly, with true feline disdain, then loped along the road in front of us for a full minute. (I counted, holding my breath.) Then, a few minutes later, on the side of a dusty hill, a ball of fur and a big black eye. Stafford stopped the car and we watched the giant kangaroo rat nibble for a moment. Then it was hop, hop, and a magnificent leap up the hill, like a loaded spring had shot it off. Another small hop and it was gone, over the top and into the darkness. Stafford started the car again. “Well, that was nice to see,” he said. I put a tick mark in the spreadsheet column labelled “K-RAT.” Then we drove back, continuing our small count of wild things through the night, in this harsh land growing harsher.

*Correction: An earlier version of this article misidentified the species of bat in the abandoned farmhouse.