The 26-year-old Keannan Simpson, of Yankton, South Dakota, died following a Monday afternoon crash on a rural road near Hartington.
Investigators say Simpson was driving when he lost control of his sport utility vehicle and rolled several times.
Officials say Simpson was thrown from the vehicle and taken to a Yankton hospital, where he died.
A 25-year-old Yankton woman who was riding in the SUV also was thrown in the crash and is in Sioux Falls hospital in critical condition.
The Cedar County Sheriff’s Office says neither Simpson nor his passenger were wearing seat belts.