GREAT FALLS — One man has been found dead and his half-brother is missing in Yellowstone National Park.
Search and rescue crews found the body of Mark O’Neill along the east shore of Shoshone Lake on Monday.
O’Neill, 67 years old, from Chimacum, Washington, and his half-brother, Kim Crumbo, 74, from Ogden, Utah, were reported overdue by a family member on Sunday, September 19 from a four-night backcountry trip to Shoshone Lake.
Park crews on Sunday found a vacant campsite with gear on the south side of Shoshone Lake, as well as a canoe, paddle, personal flotation device, and other personal belongings on the east shore of the lake.
Crews found the body of O’Neill along the east shore on the morning of Monday.
Search and rescue efforts continue with 10 crew members on foot in the area Tuesday, September 21 to locate Crumbo. Grand Teton National Park interagency ship and crew are also assisting with air operations.
Yellowstone National Park said in a news release that O’Neill and Crumbo are both National Park Service retirees, and Crumbo is a former Navy SEAL.
Park officials said that incident is being investigated, and that "while we cannot comment further about the specifics of this investigation, we will provide updates when appropriate to do so. We ask the public to maintain distance from any law enforcement personnel, equipment, vehicles and their related activity for the safety of the public in this remote area and to protect the integrity of our work."
Shoshone Lake, the park’s second-largest lake, is located at the head of the Lewis River southwest of West Thumb. The average year-round temperature of the lake is about 48 F (9 C). Survival time is estimated to be only 20 to 30 minutes in water of this temperature.