Residents across New Mexico and Colorado hunkered down in biting wintry conditions Thursday that made roads impassable, as forecasters predicted there could be historic amounts of snow in the region.

A slow-moving winter storm was expected to drop up to three feet of snow in parts of the two states through Saturday, causing perilous road conditions and power outages.

Tens of thousands of people in New Mexico are without power as the first major winter storm of the season rolled across the northern two-thirds of the state.