Rescue crews spent their fourth straight day Sunday looking for 29-year-old Kurt Ruppert of Lake City, Fla., but found no sign of him by dusk.
King County sheriff's Sgt. Cindi West said over the past four days, 386 volunteers from 19 different agencies have searched an area of about nine square miles for the missing man. The Sheriff's Office helicopter also spent three days searching from the air.
In addition, searchers also extensively combed a quarter-mile square area that they said was a "potential" area based on cell phone and the helicopter flight path data.
The Sheriff's Office said they have completed searching the areas that could be reached on foot. There are cliff areas that can't be searched due to the extreme risk to searchers. The Sheriff's Office said they will search those areas by helicopter when weather permits.
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.
He was skydiving with two friends, and they were taking turns jumping from the helicopter. The friends were waiting at a grassy landing area, but no one saw whether Ruppert's chute deployed.