On a Northern California hiking trail near the Cascades’ Mount Shasta, two all-black adult wolves and five 4-month-old pups have been captured on film. It’s the first time in modern history that a gray wolf pack has been seen in the state since its population was hunted to extinction nearly a century ago.

The California Department of Fish and Wildlife released photos Thursday showing the wolves — dubbed the Shasta Pack — rummaging around in rural Siskiyou County.

“This is an Endangered Species Act success story in the making,” Pamela Flick, with the Defenders of Wildlife conservation non-profit, told the San Jose Mercury Times.

Indeed, California’s gray wolf population was believed to be wiped out in the 1920s. Across the United States, settlers had done their best to kill them off to protect livestock and use their charcoal-colored coats. As a result, the species was listed as endangered in 1973 and, although California had no known gray wolves left, the state declared them endangered just last year.

The recent sighting comes a few years after a lone gray wolf, known as OR-7, wandered some 200 miles from Oregon’s wilderness to California’s Cascades. He has since gone back home and found a mate. But it marked the first time in a century that biologists had seen one in the state and it prompted state wildlife authorities to start working on a management plan to help them repopulate, assuming the species would start to make its way south again. Still, biologists didn’t expect a resurgence so soon.

“They have beat us to the punch on a couple of occasions now,” California’s wildlife branch chief Eric Loft told reporters Thursday, according to the Sacramento Bee.

“This news is exciting for California,” department director Charlton H. Bonham said in a statement. “We knew wolves would eventually return home to the state and it appears now is the time.”

Wildlife authorities are now trying to finalize the management plan, though it won’t be in force until the end of the year, said Karen Kovacs with the California Department of Fish and Wildlife.

But some worry that the gray wolf’s comeback could become a threat.

Ranchers are concerned that new state laws will make it difficult for them to protect their livestock and hunters have long argued that the animals kill their prey.

“If the public wants wolves maybe they should support the people that are helping feed the wolves,” Jim Rickert, who owns a ranch nearby, told the Sacramento Bee.

Wildlife advocates say such losses are nominal and well worth it.

“We have been given a second chance to restore this iconic species to a landscape they had been missing from for nearly 100 years,” Jamie Rappaport Clark, president of the D.C.-based nonprofit Defenders of Wildlife, said in a statement. “We must seize this opportunity to forge new partnerships to help wolves live in harmony with people and livestock in their California home.”

Trail cameras first spotted a suspected gray wolf in May and June and biologists set out to retrieve scat samples and set up additional cameras, wildlife authorities said. Two adult wolves were then captured on film. The whole pack was confirmed on Aug. 9.

The adult wolves are suspected to be from Oregon but wildlife authorities do not believe they are descended from OR-7, the one that wandered into California in 2011. DNA samples have been sent to a lab in Idaho to determine where the clan came from.

“We’re very interested in where did these wolves come from and who did they descend from,” Kovacs told the Sacramento Bee.

Kovacs called the new wolf pack “remarkable,” according to the Los Angeles Times. “These are very resilient critters,” she said.