UPDATE: OCT. 8 AT 2:17 PM:
The search for a missing Shoshone Lake canoer is being scaled back.
For nearly three weeks now, the search for 74-year-old Kim Crumbo from Ogden, Utah has been utilizing helicopters, boats, sonar technology and ground crews.
Yellowstone National Park says current weather forecasts call for deteriorating conditions over the upcoming week, including snow and freezing temperatures.
Limited search efforts will continue as conditions allow this year.
"All of us at Yellowstone extend our deepest sympathies to the families, friends and colleagues of both Mark and Kim," said Superintendent Cam Sholly. "I want to personally thank the teams from Yellowstone, other parks and agencies, and partner organizations who worked to help us locate Mark, and who continue search efforts to bring Kim home."
At this time the incident is under investigation and Yellowstone National Park says they do not expect to provide further updates unless notable changes occur.
UPDATE: SEPT. 22 AT 9:02 A.M.
Authorities are still searching for Kim Crumbo at Shoshone Lake in Yellowstone National Park and will keep searching for the next several days.
In a release, Yellowstone National Park asks visitors give space to any law enforcement, equipment, vehicles or associated activity for the safety of everyone and to protect the integrity of the mission.
YNP said they cannot verify details of the investigation, but said they will give updates as they can.
The investigation remains ongoing.
MAMMOTH HOT SPRINGS, WY - A search and rescue mission is underway for a 74-year-old man after his half-brother was found dead along the east shore of Shoshone Lake in Yellowstone National Park.
67-year-old Mark O’Neill and 74-year-old Kim Crumbo, were reported overdue by a family member Sunday, Sept. 19 from their four-night backcountry trip to Shoshone Lake.
Park crews found an empty campsite with gear on the south side of Shoshone Lake that night, as well as a canoe, paddle, personal flotation device and other personal belongings on the east shore of the lake.
Crews located O’Neill's body along the east shore on the morning of Monday, Sept. 20.
Today, search and rescue efforts continue with 10 crew members on foot in the area to locate Crumbo. Grand Teton National Park interagency ship and crew are also assisting with air operations.
Both O’Neill and Crumbo are National Park Service (NPS) retirees, and Crumbo is a former Navy Seal.
The incident is under investigation.
YNP is asking the public to keep their distance from any law enforcement personnel, equipment, vehicles and their activity in this remote area.
This is a developing story.