Colorado trail runner, 49, vanishes while trying to complete grueling 28-mile hiking route in Rocky Mountain National Park: Search enters day five

An experienced 49-year-old trail runner has been missing for six days after he vanished while on a grueling 28-mile hike in Rocky Mountain National Park.

Search teams are desperately combing the remote Colorado landscape looking for Chad Pallansch, who was last seen at around noon on Wednesday.

The software engineer from Fort Collins, Colorado, parked his car at the North Inlet Trailhead on the west side of Rocky Mountain National Park, officials said.

The 5ft 7in marathon runner began his expansive route at the East Inlet Trailhead near Grand Lake on Wednesday afternoon.

Park officials said Pallansch was planning to cross the Continental Divide along several established trail routes. 

An experienced 49-year-old trail runner has been missing for six days after he vanished while on a grueling 28-mile hike in Rocky Mountain National Park. (Pictured: missing Fort Collins man Chad Pallansch)

Search teams are desperately combing the remote Colorado landscape looking for Chad Pallansch, who was last seen at around noon on Wednesday

Pallansch (pictured), a software engineer from Fort Collins, Colorado, parked his car at the North Inlet Trailhead on the west side of Rocky Mountain National Park, officials said

But his journey also involved off-trail traverse of some steep talus slopes - which are naturally occurring inclines comprising loose rocks which have fallen from surrounding cliffs. 

Pallansch was reported missing on Thursday, and park rangers confirmed his vehicle is still parked at the North Inlet Trailhead on the west side of Rocky Mountain National Park.

Some 55 responders, including 38 rescuers in the field, have been involved in the mammoth rescue mission which entered its fifth day on Monday. 

They are contending with strong winds to comb vast swathes of the 265,807-acre national park, officials said. 

Efforts are focused on the Boulder Grand Pass, Mount Alice, McHenry's Peak, Arrowhead, Stoneman Pass, Chiefs Head Peak, Thatchtop, Powell Peak and Andrews Glacier areas. 

Teams are also searching trails on the west side of the park which could have been part of Pallansch's route. 

Along with ground crews assisted by park rangers, the multi-agency rescue mission has involved helicopter searches using a heat sensing fixed-wing flight hoping to detect signs of life.

Although Pallansch is a highly experienced trail and marathon runner who had traversed numerous routes in his local national park - including covering 14,259-foot Longs Peak more than 30 times - he had not attempted this particular route before. 

Worried family and friends described Pallansch as 5 foot 7, 155 pounds, with brown hair and blue eyes. 

The 5 foot 7 marathon runner, began his expansive route at the East Inlet Trailhead near Grand Lake on Wednesday afternoon. Pallansch (pictured) has not been seen since 

Some 55 officials, including 38 rescuers in the field, are involved in the mammoth rescue mission - which involves combing vast swathes of the 265,807-acre national park amid adverse weather conditions

He was likely to have been wearing a black ultralight jacket, black running shorts or leggings and a gray fanny pack. 

Pallansch had personal navigation with him, but the device was not designed for emergency assistance, per park officials. 

Assisting Rocky Mountain National Park Search and Rescue Team members include Larimer County Search and Rescue (LCSAR), Grand County Search and Rescue, Rocky Mountain Rescue Group (RMR), and Colorado Search and Rescue Association (CSAR). 

The State of Colorado Department of Fire Prevention and Control's (DFPC) Multi-Mission Aircraft (MMA) has also been deployed, along with Northern Colorado Interagency Helitack (US Forest Service) and a contracted helicopter with Trans Aero.

Officials have appealed to the public for help, asking anyone with information which could assist the search to contact the National Park Service Investigative Bureau Tip Line on 888-653-0009 or via email: [email protected].