Why did the panther cross the river? It sounds like the beginning of a bad joke, but the answer to the question—to get to the other side—is enough to put a smile on any conservationist’s face. At least, that’s the case in Florida, where evidence of a female panther’s river crossing has been hailed as good news for an endangered population. As Jenny Staletovich reports for The Miami Herald, officials just confirmed the river crossing, signaling a milestone for one of Florida’s most threatened animals.

The river in question is the Caloosahatchee in southwest Florida, and it’s the first time in over 40 years a female panther is thought to have crossed the river. Staletovich reports that the panther appears to have staked out new territory north of the river—a fact that could help the panther population recover if she mates with males who have crossed the river, too.

That’s a big deal for a species that once dominated the region, but is endangered today. As the U.S. Fish and Wildlife Service notes, there are fewer than 100 Florida panthers in south Florida today, and 95 percent of their original range has been lost. Before the 1800s, the cats roamed freely throughout the southeastern United States, but as the area became more settled their numbers began to dwindle. In 1832, Florida counties began to offer bounties for panther hides in an attempt to protect people and livestock from the cats. The hunted creatures declined as their habitat got smaller and smaller. Within a century, the majestic panther—Florida’s state animal—was nearly extinct.

Conservationists and wildlife officials have spent decades trying to restore panther populations. The secretive creatures traditionally have a wide range, so maintenance of their favored wetland and swamp habitats is key. Monitoring is equally important—officials use cameras and track their paw prints to determine where they live and breed. In this case, the female panther’s historic river crossing was documented by trail cameras. In a statement about the find, the Florida Fish and Wildlife Conservation Commission writes that biologists used tracks found near the cameras to verify that the river-crossing cat is, in fact, female.

Not everyone will find the growing panther population cause for celebration: As the population has rebounded, so have threats to cattle. Last year, the FWC Commission asked the U.S. Fish and Wildlife Service to consider new criteria for panther recovery in the face of the species’ growing numbers, which was a controversial move. But even as officials ponder how to balance the needs of panthers and humans, more panthers means more panther deaths. This year alone, panther deaths due to cars rose to near record numbers in Florida.

As the lone female panther prowls her newly expanded habitat, it’s anyone’s guess how she’ll affect the growing number of panthers in the area. But one thing’s for sure: A single river crossing symbolizes just how far the embattled species has come.