The men drove the truck away from the Mitchell landfill on Thursday. They were reported missing Friday. Authorities began searching the James River in Sanborn County after discovering a damaged guardrail on state Highway 37 near Letcher.
South Dakota Highway Patrol spokesman Tony Mangan says searchers found the truck in the river Saturday and recovered it Sunday. The bodies of the 61-year-old driver and 46-year-old passenger were inside.
Their names were not immediately released, and how they died is still being investigated.
The patrol says equipment failure is believed to be the cause of the crash.