The ground search for a Florida skydiver who vanished during a jump above Washington's Cascade foothills has ended without a sign of the man.

The King County sheriff's office says crews combed roughly 9 miles of an area near Mount Si for 29-year-old Kurt Ruppert on Sunday but found nothing.

She says the air search would continue.

The Lake City, Fla., man hasn't been seen since he jumped out of a helicopter at 6,500 feet on Thursday. He was wearing a special wing suit with fabric under the arms to allow him to glide like a flying squirrel.

The jumpsuit is brown and green, which will likely blend into the terrain.

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

Authorities know the flight pattern of the aircraft, but they say a number of factors have made it difficult to find Ruppert, including the suit, which could allow him to travel large distances in a short time.