ARLINGTON, Wash. -- Searchers in Snohomish County are looking for a Seattle hiker who is overdue from a week-long hike in the Cascade foothills.

Gregory Keller, 59, left the Seattle area on Oct. 27 to go hiking off the Mountain Loop Highway near Darrington.

His girlfriend reported him missing Tuesday when he failed to return as scheduled on Monday.

Snohomish County Search and Rescue found Keller's rental car parked on French Creek Road approximately 10 miles west of the town of Darrington on state Route 530.

Both ground and air searches are being conducted.

The Snohomish County Sheriff's Office said Wednesday it believes the man is lost. The man has hiking and camping experience and was well-equipped.

Anyone who may have seen Keller on the Boulder Creek Trail between Oct. 27 and Nov. 2 is asked to call Snohomish County Sheriff's Office Search and Rescue at 425-388-3523.