On Monday, September 20, park officials found the body of 67-year-old Mark O’Neill on the east shore of Shoshone Lake in Yellowstone National Park. Search and recovery efforts continue at the lake to locate O'Neill's brother, 74-year-old Kim Crumbo from Odgen, Utah.

An autopsy has been completed on 67-year-old Mark O’Neill and determined that the cause of death was exposure (hypothermia). The National Park Service’s Submerged Resources Center are using sonar equipment in order to find clues in the water. Park crews are continuing 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. The recovery efforts will continue for the next several days and will be weather permitting.

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This incident remains under investigation. Specifics of the investigation have not been released. Updates will be provided when appropriate.

If you have information about O'Neill or Crumbo that could help investigators put together a timeline of events, or if you were in the Shoshone Lake area between Sept. 12-19, you are asked to call 307-344-2428 or email yell_tip@nps.gov.

Park officials and law enforcement personnel would like to offer a sincere thank you to the public who assisted with the search. The public is asked to maintain distance from any law enforcement personnel and search crews, equipment, vehicles and their related activity for the safety of the public in this remote area and to protect the integrity of their work.

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