More than 1,000 people trying to head home for Thanksgiving have spent the night in a US airport as heavy snow and wind shut down highways across two states.
Storms on Tuesday in Colorado and Wyoming also closed schools in Nebraska and forced travellers to sleep overnight in Denver's airport after hundreds of flights were cancelled just as Thanksgiving travel moved into high gear.
The storm was heading to South Dakota, Iowa, Michigan, Minnesota and Wisconsin, while a "bomb cyclone" weather phenomenon began toppling trees, knocking out power and dumping snow as it barrelled into California and Oregon - making for a double whammy of early wintry weather.
Authorities on both sides of the California-Oregon border reported numerous crashes and closed roads. The National Weather Service urged people to wait to travel for the holiday until the weather improves.
At Denver International Airport, about 25 centimetres of snow mixed with winds that limited visibility prompted the cancellation of about 30 per cent of the airport's average daily 1,600 flights.
The storm dumped nearly 1 metre of snow in parts of northern Colorado and closed long stretches of highways there and in Wyoming.
One person was killed, and two others were injured on a major road near the Colorado ski town of Vail.
Southwest Airlines cancelled about 200 flights and a spokesman said it would take several days to get stranded passengers moving due to the pre-Thanksgiving travel crush.
Elsewhere schools and university campuses were closed.
Blizzard and wintry weather warnings extended into the Great Lakes states with the storm bringing high winds and snow to Michigan, Minnesota and Wisconsin, while snow was also expected on the weekend for parts of New England, the National Weather Service said.
Australian Associated Press