A winter storm that hit just before Tuesday evening rush hour caused a series of crashes that led to the temporary closure of northbound Interstate 25 in Monument.
The Colorado State Patrol said it's unclear how many vehicles were involved, but two people with undetermined injuries were taken to hospitals.
Traffic slowed to a crawl and even to a standstill at times between Baptist Road and Monument. Conditions worsened as drivers neared the Douglas County line. County Line Road was covered in ice and caused several vehicles to slide off the road.
The pavement, still warm after several days of good weather, melted much of the wind-driven snow and turned it to ice as temperatures dropped. Visibility was poor at times.
Some of the message boards on the interstate near Monument weren't working, confusing drivers who wanted more information about the road conditions ahead. It's unclear why the boards weren't functioning.