Nicolas Cendoya, 19, and his friend, 18-year-old Kyndall Jack, went missing while hiking on Easter Sunday. They were each found separately several days later.
The Orange County District Attorney's Office said methamphetamine was found on or around March 31 in Cendoya's parked car in the Cleveland National Forest.
"The Orange County Sheriff's Department was searching his car looking for any information that might help them locate the two missing hikers and while they were looking in the car they found 497 milligrams, or a small useable amount, of methamphetamine," said Farrah Emami a spokeswoman for the district attorney's office.
Cendoya was charged with one felony count of unlawful possession of methamphetamine. If convicted, he could face up to three years behind bars.
Jack is not charged at this time, according to the district attorney's office.
Orange County officials said earlier they would not seek reimbursement for the more than $160,000 spent rescuing the pair. One deputy was seriously injured during the rescue.
There was a request for an investigation to determine if the hikers set in motion a series of events in which they should be held legally and financially responsible.
Investigators did not ask the hikers to submit to toxicology testing after their rescue.
After being released from the hospital, Cendoya told reporters that he remembered little from the ordeal beyond strange visions.
"I was just hallucinating and looking for water," Cendoya said on April 5. "I ended up just eating plants and sucking juices out of plants."
Orange County Supervisior Todd Spitzer said he's outrage that the reckless behavior cost tax payers money.
"We now know Cendoy and Jack were engaged in illegal activity," Spitzer said. "They were ingesting drugs, which obviously had some kind of effect on them to their detriment and peril."