It’s believed that there are as few as 50 Sierra Nevada red foxes left in the United States. So staff at Yosemite National Park were ecstatic when they confirmed a sighting of the elusive endangered animal—their first in nearly a century.

When a team of wildlife biologists trekked out into the backcountry in the northern part of the park, their mission was to check on motion-sensitive cameras they previously installed in the hopes of getting a glimpse of rare wildlife. Their work paid off: they learned that the cameras had spotted a fox not once, but twice, during the month of December.

Scientists aren’t entirely certain why the Sierra Nevada red fox has such a tiny population, though they name factors like deforestation, disease and competition with animals like coyotes as possible culprits. The species is so shy that it’s nearly impossible to estimate its numbers. A lack of basic ecological information makes Sierra Nevada red foxes even harder to protect, which means that though the unusual sighting is cause for celebration, there’s still work to be done.

“We’re excited to…join efforts with other researchers that will ultimately get these foxes the best chance for recovery,” said wildlife biologist Sarah Stock in a statement. Now that they know there’s a red fox in the park, Stock’s team hopes that the “hair snare” stations they set up near the cameras on their trek will yield samples of the red fox’s hair.

Once they snag some precious red hair, they hope to conduct critical DNA research. That tactic will allow them to take advantage of a precious opportunity without hurting the animal itself—and they don’t need to rely on baits, lures or anything that could spook the animal or disrupt its habitat.