Yellowstone National Park Releases Official Cause of Death for Shoshone Lake Canoer

by Amy Myers

After completing an autopsy on the formerly missing person, 67-year-old Mark O’Neill, officials found that the cause of death was exposure (hypothermia). Previously, a family member reported O’Neill and his brother, 74-year-old Kim Crumbo, missing. The two had been on a four-night backcountry canoe trip through Yellowstone National Park on September 19. O’Neill was originally from Chimacum, Washington while Chumbo was from Ogden, Utah. Both brothers were National Park Service retirees, and Chumbo was also a former Navy Seal. The search concluded for O’Neill on the 20th when rescue teams found his body on Shoshone Lake’s east shore. Efforts still continue for Crumbo.

Currently, Shoshone Lake’s water temperature in Yellowstone National Park reads around 48 degrees Fahrenheit. Meanwhile, the air temperature isn’t much warmer with a high of 49 degrees. The combination of both cold air and water conditions can easily cause hypothermia for any backcountry visitors. Without the right equipment or clothing, prolonged exposure to these conditions can be fatal. The National Park Service estimated in its initial report of the investigation that a person can only survive “20 to 30 minutes in water of this temperature.”

At the time the search began for the two NPS retirees, investigators found “a canoe, paddle, PFD and other personal belongings” at the east shore of Shoshone Lake. It is likely that the pair were canoeing at the time of O’Neill’s death. However, the NPS hasn’t found any sign of Crumbo close to the site of O’Neill or the canoeing equipment.

See photos from the investigation at Yellowstone National Park here.

NPS Uses Helicopters and Boats to Locate Second Missing Person at Yellowstone National Park

Although officials found O’Neill along Shoshone Lake, they are not ruling out the possibility that Crumbo could be located elsewhere. As a result, park officials have extended their search efforts all across the Yellowstone National Park region for any sign of the second missing person. This includes checking all nearby trails and conducting an aerial sweep via helicopter.

“During the last five days, crews swept all the trails in the area, searched the entire Shoshone Lake shoreline by boat and gridded the open water by helicopter,” the NPS stated in their September 24 release. “Unfortunately, they did not find Crumbo.”

On September 29, teams utilized sonar technology in Shoshone Lake to detect any clues under the surface. They also recruited assistance from local dog teams to help with the search on land.

“Park crews continue to search for Crumbo by foot and boat, with assistance from Grand Teton National Park’s interagency helicopter and dog teams from Western Montana Search Dogs,” NPS stated. “These recovery efforts will continue for the next several days as conditions warrant.”

NPS urged anyone with information regarding the missing person’s case to contact authorities at 307-344-2428 or [email protected]