Cause of death determined for Shoshone Lake canoer in Yellowstone, search and recovery continues for brother

MAMMOTH HOT SPRINGS, Wyo. (KIFI) – An autopsy has been completed on a 67-year-old whose body was found on the east shore of Shoshone Lake in Yellowstone National Park on Monday, Sept. 20.

The autopsy determined the cause of death of Mark O’Neill was exposure (hypothermia).

O’Neill, from Chimacum, Washington, along with his brother, 74-year-old Kim Crumbo, from Ogden, Utah, were reported overdue by a family member Sunday, Sept. 19 from their four-night backcountry trip to Shoshone Lake.

Yellowstone National Park previously referred to the brothers as half-brothers but has now corrected this as they are brothers.

Search and recovery efforts continue at the lake to locate Crumbo.

Crews from the National Park Service’s Submerged Resources Center are using sonar equipment to detect clues in the water. 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. These recovery efforts will continue for the next several days as conditions warrant.

This incident remains under investigation, and officials cannot comment further about the specifics of this investigation but will provide updates when appropriate to do so.

If you have information that could help investigators piece together a timeline of events, or if you were in the Shoshone Lake area between Sept. 12-19, contact 307-344-2428 or yell_tip@nps.gov.