SAN FRANCISCO — An adventurous young gray wolf that crossed into California from Oregon has not been documented since early April, spurring speculation that he may be dead.

Wildlife officials who track OR-93 through his radio collar said he stopped emitting “pings” April 5 in San Luis Obispo County, which is roughly midway between San Francisco and Los Angeles. But officials also have not picked up a “mortality signal” from the 2-year-old’s collar, which indicates when a wolf has not moved for at least eight hours, the Los Angeles Times reported over the weekend.

The wolf’s radio collar could be broken or malfunctioning due to dead batteries, said Jordan Traverso, a spokeswoman for the California Department of Fish and Wildlife. He may be dead or running wild with a Central Coast pack that no one knew existed, she said.

“We’re trying to keep hope alive,” she told the news publication.

Biologists Hopeful OR-93 Still Alive

Biologists in Oregon fitted OR-93 with a GPS tracking collar in June, near the Portland area where he was born. He left the pack and crossed into California, padding south to an agricultural area near Fresno before heading west to the Central Coast. That the gray wolf made it so far was remarkable given that he had to cross three busy highways, wildlife experts said.

State biologists in Oregon and California said they plan to fly over his path with hopes of picking up his signal.

Millions of wolves thrived throughout North America until the 19th and 20th centuries, when they were eradicated by government. The U.S. Fish and Wildlife Service removed the gray wolf from the federal endangered species list after determining the overall population was stable.

There are an estimated 6,000 wolves living in the lower 48 states of the U.S. Fewer than a dozen wolves live in Northern California.

Recent claims of OR-93 sightings, including blurry, far-off photos of grayish dog-like creatures and of “wolfish” looking paw prints in wet sand give hope that he has survived. Beth Pratt, California regional executive director for the National Wildlife Federation, certainly hopes so.

“The ultimate Hollywood ending of this mystery,” she added, “would be for OR-93 to settle down with a surfer girl canine in Malibu and raise a pack of cute pups.”