Search efforts to find Mark Sinclair have been scaled back in Glacier National Park/NPS HO

Search efforts for a Montana man who went missing in Glacier National Park back on July 9 have been scaled back, though an investigation into his disappearance will continue.

Active search efforts for Mark Sinclair, 66, began the morning of July 9 in the Logan Pass area and continued through July 18. The overall search area encompassed numerous drainages east and west of the Continental Divide, including Upper McDonald Creek, Mineral Creek, Swiftcurrent, and Belly River drainages.

Trails and off-trail search areas included Flattop Mountain, the Highline from Logan Pass to Goat Haunt, Swiftcurrent Pass, the Loop, and Hidden Lake. Other associated trail areas attached to the Highline were also searched. Aerial searches included the entire spine of the Continental Divide on both sides from Logan Pass to 50 Mountain.

The search area is characterized by steep slopes with cliff faces frequently more than 100 feet high, gray rocks that act as camouflage, and dense shrubs that conceal the ground. Searchers also encountered high winds and heavy rain and hail.

Flathead County Sheriff’s Department -- including ground patrols, canine units, a search drone, and a volunteer search and rescue division -- assisted Glacier National Park Search and Rescue team members. Two Bear Air and the U.S. Forest Service provided daytime aerial search capacity and nighttime infrared flights. The U.S. Geological Survey also assisted with search drone support.

Sinclair is still considered a missing person, according to a park release. The search effort has been moved to a “limited continuous mode,” meaning that active searching will not occur every day, but will continue in a reduced capacity with patrols. The park’s investigation will actively continue in hopes of gaining further information about his whereabouts. If a clue or witness report provides new information about Sinclair’s possible whereabouts or belongings, additional search efforts will follow up.

Updated missing person posters with Sinclair’s picture and description will be posted throughout the park for the duration of the summer.

Park rangers would like to continue hearing from anyone who was in the Logan Pass and Granite Park vicinity on or after July 8 who may have had contact with Sinclair or seen him on a trail, including guests at Granite Park Chalet and backcountry overnight campers.

The park has not ruled out the possibility that he may have traveled further from the Logan Pass vicinity, given the number of trails that connect directly from this area and extend in every direction across Glacier’s one million acres.

“We continue to ask the public to think back to their visits to the park last week. Additional sightings or the discovery of Mark’s belongings could help investigators identify new search tactics,” said search team Commander Ed Visnovske. “The park deeply appreciates the efforts of our county and federal partners - we could not have covered such a significant area or conducted such an in-depth search without that support.”

Sinclair was seen at approximately 2:30 p.m. on Monday, July 8, departing the parking lot towards the Highline Trail by Logan Pass Visitor Center staff. He left behind his dog, unsecured vehicle, and car keys.

Two visitors called the tip line once the search began, and reported seeing him between Haystack Butte and Granite Park Chalet on the Highline Trail in the early evening on July 8. No other verified sightings have been received.

Members of the public who have information about Sinclair’s last seen whereabouts are urged to call the tip line at 406-888-7077.