The pronghorn tops out around 60 mph, which makes it the fastest land animal in North America and the second-fastest on Earth behind the cheetah. It is built for exactly one job: spotting trouble across miles of open country and simply leaving. Huge eyes, oversized windpipe, a heart that would look ambitious on an animal twice its size.<\/p>\n
What it never learned to do is jump. Pronghorn evolved on plains with nothing vertical on them, and High Country News<\/a> notes they have trouble clearing fences and other barriers. A six-foot barrier that a whitetail deer hops without breaking stride functions, for a pronghorn, like a wall.<\/p>\n So when a utility-scale solar farm went up across 1,100 acres of grassland in northwestern New Mexico, wrapped in the tall fencing the law requires for sites like it, the reasonable bet was that the local herd had lost that ground for good. Seventy-five GPS collars are now saying something more interesting. The animals are not going around the farm. They are walking through it, threading the gaps between the fenced panel blocks like they have read the site plan.<\/p>\n The San Juan Solar and Storage Project is a 200-megawatt solar facility with a 100-megawatt battery near Farmington, in New Mexico’s Four Corners. It occupies 1,100 acres a few miles from the San Juan Generating Station, the coal plant that shut down in 2022 and lost its four 400-foot smokestacks to demolition crews in 2024.<\/p>\n That location is not sentimental. Developer D. E. Shaw Renewable Investments<\/a> built the project as capacity replacement for the retired coal units, feeding the grid through the dead plant’s existing interconnection under a 20-year power purchase agreement with Public Service Company of New Mexico. Construction wrapped in the fall of 2024.<\/p>\n Here is the detail that turned an ordinary solar build into a wildlife experiment. The land under it came with public roads, a crowd of private landowners, and deep dry washes called arroyos cutting through it. Rather than fight all that, the builders carved the site into nine individually fenced arrays plus a battery yard, with open passages running between the blocks.<\/p>\n Those passages exist because of property lines and drainage. Wildlife was not the reason. It just turned out to be the beneficiary.<\/p>\n Wildlands Network, a conservation nonprofit, saw the construction coming and launched one of the first studies of its kind at an active American solar facility: it wired up the herd while the panels were still going in. Backed by a $1.7 million award from the Department of Energy’s Solar Energy Technologies Office, the group’s biologists fitted GPS collars on 75 female pronghorn across two study areas, one around the San Juan site and a second on the Navajo Nation in eastern Arizona.<\/p>\n Since March 2024, every collar has reported its position once an hour, around the clock. By this spring the project had banked over 1 million GPS locations and more than 5 million trail camera photos<\/a>, which is a staggering amount of homework about one animal and one fence line.<\/p>\n The early returns cut against the doomsday scenario. Of the 30 collared females living near San Juan Solar, 18 have come within 328 feet of the fencing. The researchers went looking for a buffer zone, some distance at which pronghorn refuse to approach, and so far they cannot find one.<\/p>\n And the passages are getting used. Every single gap between the nine arrays has recorded pronghorn traffic to some degree, according to the project’s May 2026 update. The fastest land animal in the Americas is treating a 1,100-acre industrial site less like a wall and more like a maze it has already solved.<\/p>\n Because the gaps came from surveyors and arroyos instead of biologists, they vary wildly. Some passages are wide and short, others long and pinched, and they sit next to everything from flat grass to cliff-edged washes and county roads. That messiness is exactly what makes San Juan useful as an experiment. It is nine different corridor designs tested on the same herd at the same time.<\/p>\n The collar data published by Wildlands Network<\/a> shows the animals are picky in ways a siting map would never predict. The biggest, most open passages get the heaviest traffic, and the longest, narrowest ones get almost none. Then the pronghorn broke their own rule and used the narrowest passage on site, which also happens to be the shortest, when food and water sat on the other side.<\/p>\n Terrain matters just as much as geometry. The largest passage has a deep arroyo running through it with cliffs the animals cannot cross, and on its western edge the fence was built only about 100 feet from that arroyo. The collars show pronghorn mostly refusing to squeeze through that pinch point, even inside a passage they otherwise like.<\/p>\n In short, the animals are not reading the corridor. They are reading what the corridor gets them to. A gap that leads to water earns traffic. A gap that leads to a cliff and a fence does not, no matter how generous it looks on a map.<\/p>\n The reason biologists expected the worst in New Mexico is that the only comparable American study found it. The 80-megawatt Sweetwater facility, Wyoming’s first utility-scale solar plant, went up in 2018 with a single continuous fence around the whole thing, and researchers had pronghorn collared there before construction started.<\/p>\n The results were rough. A follow-up study in Ecological Solutions and Evidence<\/a> tracked the herd for five years after the build and found the avoidance never faded: fewer encounters near the site, more time spent away from it, and behavioral changes reaching almost a mile beyond the fence. The habitat loss extended far past the acreage the panels actually occupied.<\/p>\n One farm sealed with a single fence, one farm broken into nine blocks with gaps. One herd retreated, the other moved in. The New Mexico team is careful not to declare the passages the proven cause, and the two sites differ in plenty of other ways. But the design contrast is the obvious suspect, and it is the exact question their next paper is built to answer.<\/p>\n It fits a pattern this industry keeps bumping into. Oregon just permitted 406,000 panels on the condition the developer leave a 600-foot gap so deer and elk can still reach their water<\/a>, a corridor nobody has built or tested yet. In California, an endangered kit fox moved into two solar farms and raised pups inside the fence<\/a>.<\/p>\nThe solar farm sits on the bones of a coal plant<\/h2>\n
Seventy-five collars, one ping every hour<\/h2>\n
The aisles were never designed for wildlife<\/h2>\n
Wyoming’s pronghorn did the exact opposite<\/h2>\n