A search has been suspended for a skydiver who vanished during a jump above Washington's Cascade foothills.

King County sheriff's Sgt. Cindi West says 100 searchers were out near 4,200-foot Mount Si east of Seattle early Sunday, looking for 29-year-old Kurt Ruppert of Lake City, Fla.

The search was suspended later Sunday, the fourth day of looking for Ruppert.

Ruppert hasn't been seen since he jumped out of a helicopter at 6,500 feet Thursday afternoon, wearing a special wing suit with fabric under the arms to allow him to glide like a flying squirrel.

Crews narrowed their search area Saturday, based on data from Ruppert's cellphone and the helicopter's flight path.

West says searchers checked areas that could reached by foot. A helicopter search will continue as weather allows.