A family of grey wolves has been discovered in Northern California, making it the second wolf pack to be spotted in the state since the species went extinct in 1924, state wildlife officials said on Wednesday, according to AP.

At least three pups, a female grey wolf and her mate were found in Lassen National Forest, the Department of Fish and Wildlife said. The grey wolf cups are believed to have been born in the forest itself.

The male wolf is the son of OR7, a wolf with a tracking device that was the first of its kind in almost a century to migrate into California from Oregon, the department said.

Biologists found evidence of wolf presence at the Lassen National Forest in May. They have been surveying the forest since then. On June 30, the biologists managed to capture the 75-pound female grey wolf and fitted her with a tracking collar. An examination later revealed that she had recently given birth to cups.

A day later, when biologists of the Department of Fish and Wildlife returned to the area for a follow-up check on the female, they discovered that a nearby trail camera operated by the US Forest Service had captured photos of the mother and her pups. The grey pups were also photographed playing in front of the camera.

Officials said they had also found some tracks in the nearby Plumas County.

This is the second pack of grey wolves found in California since they were killed off in the 1920s. The first breeding pair produced five pups in Siskiyou County in 2015. The family of seven has not been detected since May 2016, though one of the pups was detected in northwestern Nevada in November 2016, the department said.