NORTH BEND, Wash. -- A rescue mission became a recovery mission after a hiker who fell about 200 feet in rough terrain on Mount Si died from his injuries Thursday, reported KIRO 7 Eyewitness News.

The 27-year-old man was hiking with another man in a steep section called the Haystack when the accident occurred at the 4,200-foot level at about 1 p.m., the King County Sheriff's Office said.

Once the victim's 22-year-old friend was able to get cell phone reception, he called 911 and King County Search and Rescue personnel responded, police said.

Thick fog in the victim's location made an airlift impossible, but the Guardian One rescue helicopter was able to drop rescuers at the 2,300-foot level.

The man performed CPR on the victim and kept in touch with rescuers as they ascended up mountain, Chris Bedker of the King County Sheriff's Office told KIRO.

Bedker said the terrain was difficult, and with thick fog on the mountain, it was hard to locate the victim.

King County sheriff's detectives said the victim died shortly after medics arrived.

Detectives said their main concern now is to get the survivor and rescuers off the mountain safely, which could take up to two hours.

The 4,167-foot-tall mountain in North Bend is part of the Cascade Range.