Ruppert, 29, of Lake City, Fla., hasn't been seen since he leaped from a helicopter 6,500 feet in the air near Mount Si Thursday afternoon while wearing a wingsuit.
The King County Sheriff's office said nearly 400 volunteers searched about 9 square miles of rugged terrain by ground and air.
The target search area was based on the flight path of the helicopter that took Ruppert aloft and information from his cellphone immediately after his jump.
The sheriff's office said some cliff areas could not be reached on foot and a helicopter would cover those areas as weather permits, The Seattle Times reported.
2014: The Year in Music [PHOTOS]