The search for a missing seasonal employee at Glacier National Park entered its fourth day on Thursday, Sept. 1, after a weather front brought lower temperatures and rain and snow in the mountains.

The search for Jacob "Jake" Rigby, 27, began Monday after he failed to return from a day hike on Sunday. The search focused on the southern part of the Park after Rigby's vehicle was found at the Fielding Trailhead along U.S. 2 at mile marker 192.

A piece of red plastic mesh was found on Wednesday, and searchers were trying to determine if it belonged to something Rigby was wearing or carrying.

Seventeen people remained in the search area Wednesday night through inclement weather. The terrain is extremely steep and treacherous and typically only sees skilled hikers and climbers. Personnel from the Flathead National Forest and Flathead Valley Search and Rescue joined Park rangers in the initial search.

Park rangers believe Rigby may have signed the summit register on top of 8,446-foot high Brave Dog Mountain on Sunday. After this discovery, searchers concentrated on the climbers route from Brave Dog to 8,852-foot high Mount Despair, between the Ole Creek and Park Creek drainages.

On Wednesday, searchers reached the summit of an unnamed 8,888-foot high peak between Brave Dog and Despair. Park spokesperson Denise Germann said the lack of a signature in the tattered register at the summit of Peak 8888 did not prove or disprove that Rigby was there.

Searchers believe Rigby was hiking an extreme mountain traverse with challenging terrain in the Soldier Mountain, Sheep Mountain, Brave Dog Mountain, Mount Despair and Eagle Ribs Mountain area north of U.S. 2 near the Snow Slip Inn.

Rigby, a 2002 graduate of Johnsburg High School, in Illinois, has a geology degree from the University of Illinois at Urbana-Champaign. He worked on the exotic plant program in Glacier Park.

Park officials say Rigby is an avid and skilled hiker and is familiar with the Park. He has excellent scouting capabilities and enjoys hiking off trail.

He is 6 feet tall with brown, of medium build with short curly hair. He was probably wearing a blue T-shirt, blue Patagonia hiking shorts, size 10 La Sportiva boots with Vibram soles and possibly gaiters and carrying a white/silver Mamut daypack. Posters with Rigby's photo and key information have been posted in the Park and other locations.

Anyone who may have been in the area in the Ole Creek or Park Creek drainages on Sunday and may have seen Rigby is encouraged to contact park dispatch at 406-888-7800 or 406-888-5800.