The FBI has joined the investigation into the disappearance of two California men who were reported missing in Yakima County during their trip to a concert at the Gorge Amphitheatre early this month.

Josiah “Jo” Hilderbrand, 25, of Piercy and Jon Cleary, 48, of Huntington Beach were last seen June 7 en route to a Dead & Company show. The band features several former members of the Grateful Dead.

The car Hilderbrand and Cleary were traveling in — a light blue 2004 Honda Civic hybrid with California plates — was found abandoned June 8 in an orchard at 8100 Lateral B Road in Toppenish, said Casey Schilperoort, public information officer for the Yakima County Sheriff’s Office.

FBI spokesman Steve Bernd of Seattle confirmed that the agency is involved.

“At the request of the Yakima County Sheriff’s Office, the FBI is assisting with its investigation into the disappearance of two men,” Bernd said in an email. “The FBI routinely offers assistance to our law enforcement partners, in order to provide additional personnel and specialized resources.

“As the investigation is ongoing, no additional information is available at this time,” he said.

Hilderbrand’s family is offering a $15,000 reward for information leading to his location. He is 5 feet 8 inches tall, weighs 165 pounds and has light brown wavy hair and blue eyes, notes a flyer being circulated by family and friends. He has a cartoonish wolf head tattoo on the left side of his neck and an Egyptian-looking cat on the right side, according to a post on the Yakima Scan Missing Persons page on Facebook.

There is a GoFundMe account created for Hilderbrand’s family by a friend. Family and friends are also sharing a link to a missing person flyer that can be printed.

A separate reward is offered for information about Cleary, and friends recently created a GoFundMe account to raise money to cover his family’s expenses to travel to Washington and continue the search.

Authorities conducted a search warrant on the car the men were traveling in, Schilperoort has said, and “didn’t find much.” They continue to try to document where the two men went, where they were last seen and more, he said.

Those with information regarding the men’s whereabouts, what happened to them or events leading up to their disappearance are asked to call the sheriff’s office at 509-574-2500, reference case No. 19C09726, or Yakima County Crime Stoppers at 1-800-248-9980.

Reach Tammy Ayer at tayer@yakimaherald.com or on Facebook.