Snohomish County Search and Rescue crews are mobilizing in response to emergency beacon alerts being sent from a 39-year-old Seattle man near Mt. Persis.
Crews have not made contact with the man yet and are not sure if he is lost or hurt.
The first emergency beacon alert came in at around 10:30 p.m. Wednesday night.
Search and Rescue crews and a rescue helicopter will begin search efforts at daylight.