RENO, Nev. — The U.S. Fish and Wildlife Service is refusing to take the gray wolf off the list of endangered species in Nevada, even though agency biologists acknowledge the animals have been extinct in the state for decades.

In fact, while the University of Nevada's athletic teams are nicknamed the Wolf Pack, there's general agreement that the mountains and high desert valleys that boast mountain lions, black bears and bighorn sheep haven't been home to more than a handful of wolves for centuries.

The Nevada Division of Wildlife petitioned the federal agency to delist the wolf in Nevada, primarily to give the state more options to manage the wolf population in case the carnivores wander here after being reintroduced elsewhere.

In rejecting the petition earlier this month, the Fish and Wildlife Service said the Endangered Species Act makes it clear a species cannot be removed from the protected list unless it's documented the animal was listed in error and that either the species never existed or could not exist in an area because of unsuitable habitat.

"We agree with NDOW, that wolves never were abundant in the state, that there is limited habitat available for wolves in the state and that there probably never was a self-sustaining wolf population here," said Jody Brown, the federal agency's deputy field director for Nevada.

"So we don't dispute that there weren't high numbers historically. But that's not enough to say they never did exist or never could exist," she told The Associated Press.

Defenders of the wolf point to several American Indian tribes in Nevada who feature wolves in many of their stories and celebrations as evidence they must have once been a significant presence.

And despite the arid nature of most of the state, conservationists say there are significant parts of Nevada that someday could again support the creatures that once stretched across most of North America.

Neither federal nor state officials are sure the last time a gray wolf was confirmed in Nevada. In recent years, some ranchers in northeast Nevada claimed to have seen wolves, but they may have been coyotes.

State officials point to "Mammals of Nevada" — a book by E. Raymond Hall first published in 1946 — as the most authoritative source on the topic.

It confirms a sighting in extreme northwest Nevada in 1941 by Fred Vogel. Vogel had worked for the U.S. Bureau of Biological Survey killing wolves in the Great Plains and later killing coyotes in Nevada and therefore was presumed to be "competent to distinguish the northern wolf from the coyote," Hall wrote.

Vogel knew of only one wolf killed in all his time in Nevada. In 1916 or 1917 he saw the skin of one trapped near Little High Rock Canyon in the Black Rock Desert, the book said.

Wolf sightings were more frequent in northeast Nevada, although still rare. One was killed in 1922 at Gold Creek in Elko County and a state trapper caught one near Mountain City in 1923.

In 1941, animal control officers reported that only six wolves had been taken in Nevada in the previous two years — three in Elko County, one near Eureka, one in White Pine County and one north of Reno near the California border.

The closest known population of wolves to Nevada today is more than 100 miles north, in Idaho's Boise and Sawtooth national forests, according to the Fish and Wildlife Service.

Chris Healy, spokesman for the Nevada Division of Wildlife, said the state wants the wolf off the protected list "so if it ever did become established in Nevada, we'd have more management flexibility."

"We've spent an awful lot of time establishing elk in the Jarbidge area and other areas. If they started devastating the elk herd and we didn't have reasonable management options to keep the numbers down, we could lose a precious resource to our agency and to hunters," Healy said.

The Nevada wolves — if there are any — are considered part of a distinct population segment that stretches through the Northern Rockies.

The Fish and Wildlife Service last year sought to delist the gray wolf through that entire range, arguing that the wolf population has recovered enough that federal protection no longer is needed. But conservation groups sued and a judge struck down the decision in January, saying the agency violated proper procedures.

Brown said the agency would try again.

The Sierra Club and Defenders of Wildlife were among the groups that opposed delisting.

"We really don't want to be managing wide-ranging species like wolves on a state-by-state basis," said Bart Semcer, the Sierra Club's Washington, D.C., representative.

"The Endangered Species Act works at a landscape level. That is one of the reasons it has been successful at recovering species like the bald eagle — it doesn't stop at a particular state boundary," he said.

As for the University of Nevada Wolf Pack, the school's Web site says its athletic teams were known as the "Sagebrushers" and then the "Sage Hens" in the late 1890s and 1900s. In 1923, they became the Nevada Wolves and by the late 1920s were the Wolf Pack.

"The Sierra Nevada mountains, located immediately to the west of Reno and prominent on the city's skyline, were and still are the home to numerous wild wolves," the site says.

Perhaps at one time, but not any more.

Jamie Klund, Nevada's sports information director, said the historical information on the Web site will be updated.

Amaroq Weiss, director of Western species conservation for Defenders of Wildlife, said wolves must have been prevalent in Nevada and California given the history of references to wolves in tribal cultures.

"The Paiute tribe has several creation stories that use the wolf as well as several tribes throughout California. It's a strong indication that the wolf must have been there in real numbers," she said from Ashland, Ore.

Weiss also pointed to a paper published in 2001 by Malcolm Margolin, which said there were roughly 80 tribal languages in California when Europeans arrived in California in the 18th century "and virtually all had distinct words for wolf, dog, fox and coyote — so they knew there was a difference."

Hank Vogler, a longtime rancher and hunter in eastern Nevada's White Pine County, is among those who wanted the wolf taken off the protected list in Nevada. He said Idaho's wolves already have started crossing the Snake River into Oregon and it's only a matter of time before they show up in Nevada.

"I'm for anything to keep them from being elevated into some high and noble position to where we can't do anything about it if they show up," he said.

Vogler said that under the Fish and Wildlife Service's way of thinking, dinosaurs might as well be listed as endangered.

"How 'bout the wooly mammoth? When was the last time you saw one of those? Or the saber-tooth tiger?" Vogler said. "How far back do you want to go?"