Rescue teams are resuming the search for three men reported missing after a large mudslide in western Colorado.

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.

An entire ridge is believed to have broken away Sunday evening. Lt. Phil Stratton in the Mesa County Sheriff's Office described the slide as unbelievably big.

"The debris field is estimated to be four miles long and two miles wide, with earth now piled 250 feet deep in places," Stratton said on Sunday.

According to a press release from the Mesa County Sheriff’s Department, a witness told dispatchers they heard a noise like a freight train as the earth moved. The slide was first reported around 6:15 p.m. on Sunday. Rescue crews were on scene shortly after the ground gave way and officials have closed the area to the public, warning that it's still highly unstable and dangerous.

The three men reported missing all live in the area of the slide. The Sheriff's office says it hasn't gotten any reports of damaged structures, but is waiting to do a fuller assessment in the light of day Monday. No major roads were impacted by the slide.

Rain had fallen in the area most of the day, and authorities believe it was likely a factor.