( CNN ) -- About 130 trained mountain rescuers returned before dawn Sunday to search for a skydiver who went missing three days ago in the mountains east of Seattle , a spokeswoman for the King County Sheriff 's Office said . `` We do n't know if he 's on the ground . We do n't know if his parachute deployed , and he 's stuck up in a tree somewhere , '' Sgt . Cindy West said . Sunday 's search began at 5 a.m. , she said . Kurt Ruppert , of Lake City , Florida , was reported missing Thursday by two friends after he failed to show up at a landing zone , authorities said . Ruppert was making his second jump from a helicopter above Washington 's rugged Cascade Mountains when he went missing , they said . Authorities believe Ruppert jumped from an altitude of about 6,500 feet while wearing a special jumpsuit known as a `` wingsuit , '' which allows a person to soar and glide before deploying a parachute . Searchers used the trajectory of the helicopter and cell phone signals from Ruppert 's phone to narrow down the rescue area . Authorities did not say how they determined the cell phone signal , and it was not clear whether he attempted to use it or if authorities were able to track the signal another way . Two friends who shared the price of a helicopter rental with Ruppert did not see whether his parachute opened on his second jump , authorities said . Ruppert was not dressed for enduring Washington 's cold overnight climate in the mountains . `` We still consider this a rescue mission , '' West said . `` We realize that it is cold outside . But we are hoping he is alive and his parachute got stuck in a tree or something . '' CNN 's Chelsea J. Carter contributed to this report .
NEW : Sunday search began at overnight , police say . Ruppert , 29 , went missing Sunday after he jumped out of a helicopter . Kurt Ruppert was parachuting over Washington 's the mountains east . He was wearing a special `` wingsuit '' when he made the jump .