Joseph MacGregor, 33, was swimming with a group of family and friends in one of the "hot pots," or deep, natural thermal pools that are clustered in a field about 5 miles west of Meadow, said Millard County sheriff's Lt. Rob Clark.
At about 4 a.m., two witnesses saw MacGregor go under the surface, Clark said. He did not reappear after about 2 minutes, and the witnesses called 911.
Responders initially could not find the man in the water; a diver then searched the pool and found the man's body beneath an underwater rock ledge.
“When they brought him up, he did have some cuts and scrapes on his head,” Clark said; authorities believe MacGregor may have been caught under the rock ledge.