A temperature drop of nearly 60 degrees in the Centennial State means rare sights from a late-spring storm that promises to cover the ground in parts of the state with snow.
More than a foot of snow fell in places like Black Forest and Aspen Park.
As of Saturday morning, more than 50,000 were without power.
The frozen precipitation began falling across large parts of the state by Friday afternoon.
Videos from communities such as Castle Rock, Lone Tree and Aurora showed the first flurries coming down.
National Weather Service meteorologists said because the state has been so warm, it would take a while before the snow started sticking to the pavement.
Pavement temperatures from the Loveland Pass area were around 40° degrees, causing the frozen precipitation to quickly melt.
Officials warned hazardous travel conditions were expected along the I-70 corridor in the higher elevations through Saturday morning.
The inclement weather also forced Major League Baseball to postpone the game between the Colorado Rockies and the New York Mets until at least Saturday afternoon.
By the time the event is over, forecast models show Denver could pick up as much as five inches of snow over a foot possible in higher elevations.