No serious injuries were reported, state police Sgt. Ann Wojas said.
Up to 3 inches of snow fell in the area during the night.
Wojas said the midmorning crash involved 10 cars and 12 tractor-trailers about three miles east of the Michigan City exit on I-94.
"I was coming down that hill there and all of a sudden I saw all these cars and trucks flaring left and right," Todd Skiles of Westland, Mich., told The (Michigan City) News-Dispatch. "Everybody started smashing up. Then I saw this semi coming from behind. If (the semi driver) wasn't such a great driver, this could've been a lot worse."
Wojas said at least 70 wrecks were reported Wednesday morning in her district, which includes interstates 80 and 94, and troopers in the Muncie-Marion area reported several crashes and slide-offs on Interstate 69.
"It's due to motorists driving too fast for the road conditions," state police Sgt. Rod Russell said.