The search continues for a missing former marine from Texas who was last seen a week ago.

Rock Stanley, 75, was last seen Aug. 23, according to a missing adult notification from the Las Vegas Metropolitan Police Department that was shared by the Red Rock Search and Rescue team.

Stanley was last seen in the Mount Charleston area of Clark County, Nevada, wearing a yellow jacket with gray shorts and a blue backpack. Hikers reported seeing him around the North Loop Trail. 

"He has done this trail before, and he always makes it home about 6 p.m." Courtney Stanley, Rock’s granddaughter, told KSNV-TV. "He's done this so many times, and it's never thought, you know, this would happen to him. He's experienced, he's smart. Just was completely unexpected."

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Missing 75-year-old Rock Stanley

Rock Stanley, 75, was last seen Aug. 23, 2022, in Las Vegas, Nevada. (Las Vegas Metropolitan Police Department)

The active senior visited the mountain to hike the trails once a year for the last 30 years, his granddaughter said. Last Tuesday, he decided to go solo even though he normally hiked with a partner.

People who saw Stanley said he appeared disoriented. 

"They said that he was asking people, where are we? Where are you? And just seeming kind of confused," she added. "They noticed his legs were shaking and she (a hiker) remembers thinking to herself that this is the beginning of the trail, you know, he probably needs to turn back."

The only thing Courtney believes could have caused the unusual behavior is the new medication her grandpa was recently put on. 

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The family reportedly did hear from Stanley after he didn't return to the lodge at which he and his wife were staying. They're not sure if the information he provided about being with someone who was helping him was true, or if he was disoriented. The last contact was Aug. 24.