The three passengers from vessel one fell overboard in a rapid after launching near Shoshone Power Plant. 

one of the three passengers swam for a long time and eventually became unresponsive. and when brought to shore he was unresponsive. He was pulled from the water and CPR was attempted but was unsuccessful. Coroner report notes high levels of drugs in system which possibly led to an increased heart rate and blood pressure, but the ultimate cause of death was drowning
COLORADO RIVER
Glenwood Springs              