A park visitor snapped pictures of what appears to be a gray wolf on the North Rim of the Grand Canyon, in what is potentially the first sighting of a wolf in the area since the 1940s, according to a report from Reuters.

The U.S. Fish and Wildlife Service is working with the National Park Service to confirm the sighting. Federal biologists are presuming it’s an authentic sighting unless proven otherwise.

The Grand Canyon is inside the gray wolf’s historical range—their habitat once stretched across the entire country—but the only extant gray wolf populations are in the northern Great Lakes and northern Rockies.

It’s suspected that this wolf migrated from the northern Rockies. It’s also possible that the wolf is a Mexican gray wolf—there are wild populations of that subspecies in southeastern Arizona and western New Mexico—but the wolf pictured appears to be larger than a Mexican wolf.

This sighting comes as the Obama administration considers removing Endangered Species Act protection for gray wolves across the country. Noah Greenwald, an executive at the Center for Biological Diversity, said the sighting underscored the continued need to protect wolves. The sighting “really highlights the fact that wolves are still recovering and occupy just a fraction of their historic range,” he told Reuters.