Authorities said strong winds with gusts up to 30 mph were delaying rescue efforts.
"As soon as the plows go through an area, the wind is blowing fresh snow right back into the roads," state highway department spokesman Jim Pinkerton said. "It is just really difficult for us to keep up against that wind and snow."
The wind and heavy lake effect snow were part of a slow-moving storm that has been crawling across the Midwest since Friday night. At least 14 deaths have been attributed to the storm, which dumped nearly 2 feet of snow in parts of Minnesota and Wisconsin before moving into Michigan and Indiana. Monday, it stretched further east, with snow in parts of Ohio, Pennsylvania and New York.
Northwest Indiana was hardest hit Monday, with up to 16 inches of snow in some areas around LaPorte. Lake effect snow develops when cold air rushes over the warmer water in Lake Michigan.
The strong wind made the storm one of the worst to hit the area in the past few years, said Beth West, the assistant director of LaPorte County 911. The blowing snow caused whiteout conditions at times, making even a giant inflatable Santa Claus sitting on the corner outside the county courthouse partially obscured.
About 70 vehicles were trapped by snow drifts Monday morning on a section of Indiana 2 in the Valparaiso area. Police said they were found warm and safe in their vehicles.
Others were trapped overnight on U.S. 30, some for more than 12 hours, LaPorte County sheriff's Deputy Andy Hynek said. Crews used front-end loaders to remove the drifts, but West said a few vehicles remained stuck Monday afternoon. Plows were trying to get to them.
"It's slow going because the winds are so atrocious out there," West said.
Truck drivers stopped at the Junction City Restaurant in nearby Rolling Prairie near the intersection of U.S. 20 and Indiana 2 for lunch, hoping the conditions would improve. They said driving was particularly difficult in areas where wind was blowing across open farmland, sweeping the snow onto highways and making it hard to see.
Truck driver Gary Stutzman, 52, of Franklin, N.H., decided to alter his route after stopping in the diner. He originally planned to go west before picking up Interstate 65 south toward Indianapolis but said he would now back track and take U.S. 31 south instead.
"I'm going to try to avoid it," he said of the storm.
Three retirees who drove 2 miles to meet at the diner for lunch said even their trip was difficult.
"We couldn't even see on the way over," said Bill Sullivan, 73, of Rolling Prairie. "It was blinding. You can't see nothing. We're going home and getting out of this crap."
At least 14 deaths in five states have been attributed to the storm. Seven people died in traffic accidents, and a 79-year-old man snow-blowing the end of his driveway in western Wisconsin was killed when a plow truck backed into him. Four men in Michigan and one in Minnesota died after shoveling or blowing snow, and Kennenth Swanson, 58, of rural River Falls, Wis., died when a metal shed collapsed from the heavy snow, pinning him under debris and about 3 feet of snow.
The upper Midwest also has been gripped by bone-chilling cold as arctic air swept in behind the storm. Wind chills were below zero in many places, and schools in Indiana, Michigan, Wisconsin and other states shut down because of the snow and cold.
Katie Muratore, a 20-year-old biology major at the University of Wisconsin-Madison, wore a calf-length overcoat with a fur-lined hood and hid her face behind a thick scarf as she hurried along a walkway between the campus and state Capitol. She usually takes the bus to class, but everyone else had the same idea Monday and she couldn't find any room.
"It's like sardines on the bus today," Muratore said.
As temperatures in the Detroit suburb of Dearborn struggled to reach double-digits Monday morning, Jeff Smith was digging out his car in his driveway - with no gloves or hat.
"Gloves make it hard to shovel and my hair is still wet. So it's either you get a cold or you mess up your hair, so I risk the cold," said Smith, 57, a 30-plus-year Ford Motor Co. employee who's glad that his job is close to home.
The 12-degree temperature didn't stop hundreds of fans from lining up hours before free tickets to Monday night's football game between the Minnesota Vikings and the New York Giants became available at 9 a.m. at Ford Field. The game was moved to Detroit after the Minneapolis Metrodome's inflated roof collapsed Sunday under the weight of heavy snow.
The Lions said about 30,000 tickets were distributed before 11 a.m. They said fans with tickets to the game that had been scheduled in Minneapolis also would be admitted and given preferred seating in Detroit. Those with tickets from Sunday's Packers-Lions game in Detroit would be admitted free with no reserved seating.
In Minneapolis, stadium officials were trying to repair the roof in time for the Vikings' next home game, Dec. 20 against Chicago.
Associated Press writers Jeff Karoub in Dearborn, Mich., Larry Lage in Detroit, Tom Davies in Indianapolis, Todd Richmond in Madison, Wis., and Patrick Condon in Minneapolis contributed to this report.