Ice-covered roads cut into Martin Luther King Jr. holiday observances from Albany, N.Y., to Fort Worth and Austin, Texas, where officials also canceled Gov. Rick Perry's inauguration parade on Tuesday because another round of ice was expected during the night.
The weight of the ice snapped tree limbs and took down power lines, knocking out electricity to about 135,000 customers in New York state and New Hampshire.
"El Nino puts a lot of extra moisture in the upper levels of the atmosphere so when that comes out of the Pacific and overrides the Canadian cold air, that's a recipe for freezing rain and sleet," reports CBS News weather analyst Bryan Norcross.
Even in Maine, a state well-accustomed to winter weather, a layer of sleet and snow on roads shut down businesses, day care centers and schools.
In hard-hit Missouri, the utility company Ameren said it would probably not have everyone's lights back on until Wednesday night. Overnight temperatures were expected to drop into the single digits. As of Monday afternoon, about 312,000 homes and businesses still had no electricity.
Missouri National Guardsmen went door to door, checking on residents, and helped clear slick roads.
About 106,500 homes and businesses blacked out in Oklahoma, some of them since the storm's first wave struck on Friday, also were still waiting for power Monday. Ice built up by sleet and freezing rain was 4 inches thick in places.
"Emergency responders are having a hard time getting to residents where their services are needed because of trees and power lines in the road," said Pittsburg County, Okla., Undersheriff Richard Sexton.
In Eastern Oklahoma heavy ice split trees like wishbones in Muskogee, reports CBS News correspondent Kelly Cobiella, and knocked out power to nearly the entire town, including the mayor's house.
The Army Corps of Engineers dispatched soldiers from Tulsa to deliver 100 emergency generators to the McAlester area. Fifty additional generators were being sent from Fort Worth, Texas, by the Federal Emergency Management Agency.
About 127,000 customers were without electricity Monday in Michigan.
More than 160 flights were canceled at Dallas-Fort Worth International Airport.
Before dawn Monday, a car slid into the path of a dump truck on an icy New York highway in Sennett, 20 miles west of Syracuse, killing the car's driver and two passengers.
"It was very icy, rainy, a snow-sleet mix, so definitely the road conditions had a lot to do with this," Sheriff David Gould said.
A wave of arctic air trailed the storm and was expected to push temperatures into the single digits in some areas. Oklahoma officials strongly discouraged travel, saying the frigid weather would refreeze slush and water on roads.
Waves of freezing rain, sleet and snow since Friday had been blamed for at least 15 deaths in Oklahoma, eight in Missouri, eight in Iowa, four in New York, three in Texas and one in Maine. Seven of the Oklahoma deaths occurred when a minivan carrying 12 people slid off an icy highway Sunday and hit an oncoming truck.
In California, three nights of freezing temperatures have destroyed up to three-quarters of California's $1 billion citrus crop, according to an estimate issued Monday. The last big freeze in California was 1998, reports CBS News correspondent Sandra Hughes, when the citrus growers lost $700 million – and this year could be worse. Other crops, including avocados and strawberries, also suffered damage.