Operations were returning to normal at the Minneapolis-St. Paul International Airport after the storm prompted Delta Airlines to cancel hundreds of flights Sunday, although hourlong delays were reported.
Airport spokeswoman Melissa Scovronski said about 60 departures and 100 arrivals were canceled early Monday, but she said she didn't expect more because the weather was clearing.
The National Weather Service reported the storm dropped 12.5 inches of snow at the airport by Monday afternoon.
The southern Minneapolis suburbs had even more snow, with Eden Prairie hitting 17 inches and Bloomington a close second at 16 inches, but the highest state total was 19 inches in Madison in far western Minnesota. The storm had dwindled by Monday evening.
The snow fell from a storm that on Sunday spanned most of the upper Midwest and dropped more than 10 inches on towns in the Dakotas, Wisconsin, Michigan, and Pennsylvania.
On Monday, the weather service said snow continued to fall across the upper Midwest and the northern part of the Ohio Valley. Forecasters declared winter storm warnings throughout those areas.
Ice downed power lines in Michigan and Ohio, leaving tens of thousands of people without electricity for at least parts of Monday. Hundreds of flights were canceled at Detroit Metropolitan Airport.
AAA Michigan spokeswoman Nancy Cain said the organization took more than 4,000 requests for assistance after spinouts and minor accidents Sunday and Monday morning. It wasn't a record, which she attributed to fewer drivers on the road because of the Presidents Day holiday.
Snowfall totals in Michigan included 11.1 inches at Burton near Flint and 10.5 inches at Port Huron, the weather service said.
In Indiana, icy road conditions were blamed for a two-vehicle crash that killed a 9-year-old near Kokomo.
In Wisconsin, the Department of Transportation advised motorists to stay off the roads unless absolutely necessary as the winter storm continued. Southeastern Wisconsin was predicted to be the hardest hit.
Minnesota Department of Transportation spokesman Kevin Gutknecht said travel conditions throughout the southern half of the state were difficult Monday, but that plows were making the roads passable.
However, he warned drivers to watch out for piled snow at entrance ramps and intersections. Small cars perched and motionless on top of packed snow were a common sight Monday morning.
"Ground clearance is a significant issue," Gutknecht said.
Minnesota State Patrol Lt. Eric Roeske said many people were driving too fast for the conditions and losing control.
"A plowed road doesn't mean full speed ahead," Roeske said.
Minneapolis declared a snow emergency on Monday, joining St. Paul and many other cities in the southern half of the state that declared them a day earlier. It was the eighth snow emergency of the season for Minneapolis, which officials said was the most it has ever declared in a single winter.
In South Dakota, transportation officials reopened parts of interstates that were closed Sunday due to the storm. Interstate 90 was reopened between Wall and Chamberlain, and I-29 was reopened between Sioux Falls and Brookings.
Associated Press writer Jeff Karoub contributed to this report from Detroit.