On Sunday afternoon, a jackknifed semi blocked both southbound lanes of Interstate 29 near the Castlewood exit.
Two other accidents occurred near the semi and four people were sent to the hospital with minor injuries.
I-29 was shut down for a few hours while crews removed the semi.
Blowing snow and poor visibility were reported at the accident.
The South Dakota Highway Patrol and Hamlin County Sheriff’s Office are investigating the crashes.