An 88-year-old with dementia left home in Washington and hasn't been seen in a week, deputies said.

Now, the search is on for the missing man.

William "Charlie" Martin was last seen Sept. 24 in Wenatchee, the Kittitas County Sheriff's Office said in a Facebook post.

His family reported him missing, and a Silver Alert was issued.

Martin's vehicle was found abandoned Sept. 26 in a remote "mountainous Colockum area," just south of Wenatchee, deputies said.

Drones, dogs and ORVs have been used to look for Martin, but he hasn't turned up, deputies said.

His search zone is in a popular hunting area, so authorities are asking hunters to check their photo feed if they have motion-sensitive game cameras.

"Please keep Charlie and his family in your thoughts. Those who want to support this effort, and this kind of effort, are encouraged to contribute or consider volunteering at your county's Search and Rescue organization," deputies said in the post.