ST. LOUIS – Snowplows and salt spreaders took to highways in the nation’s heartland Wednesday, preparing for a deadly winter storm that promised to dump up to a foot of snow in some areas.

Winter storm warnings were issued from Colorado through Illinois. By midday Wednesday, heavy snow was already falling in Colorado and western Kansas. In Oklahoma, roads were covered with a slushy mix that officials blamed for a crash that killed an 18-year-old man.

National Weather Service meteorologist Jayson Gosselin said parts of Colorado, Kansas and northern Missouri could get 10 to 12 inches of snow. Dodge City, Kan., was bracing for up to 16 inches of snow. Farther south, freezing rain and sleet were making driving treacherous.

Officials feared the winter storm would be the worst in the Midwest since the Groundhog Day blizzard in 2011, which was blamed in about 24 deaths and left hundreds of thousands without power.