The slide hit Sunday in a remote area near the town of Collbran, about 40 miles east of Grand Junction.
Mesa County Sheriff’s dispatcher Amanda Orr says three area residents are unaccounted for, and it’s unknown if they were in the area impacted by the massive slide.
A sheriff’s helicopter was surveying the slide area early Monday. The department said late Sunday it estimated the slide to be about 4 miles long, 2 miles wide and 250 feet deep in many places.
Authorities say no structures or major roads were affected.