DELTA COUNTY, Colo. — Two men are missing after they might have fallen through ice after driving a snowcat out on a lake, the Delta County Sheriff’s Office said Monday.

The Summit County Sheriff’s Office Search and Rescue team is using an unmanned underwater drone to search frozen Island Lake on Grand Mesa.

The sheriff’s office was notified on Sunday of overdue parties who were staying at the Grand Mesa Lodge.

Owner Michael Wenner told deputies that three males — Ryan Wells, 30 of Delta County, Richard Colton, 30 of Delta, and Dustin Gray, 30 of Delta — and a female — Kandi Casaus, 38 of Cedaredge — came to the lodge on Saturday and rented a room for the night.

The four failed to check out on Sunday morning and their belongings were still in the room. One of the men and the woman left the area and have been accounted for, the sheriff’s office said.

Wenner told deputies that Wells had brought a privately owned snowcat to the lodge and asked questions about taking it out on the frozen lake.

Wells was told that was not a good idea because of the 15,000-pound weight of the snowcat.

Wenner also told deputies that about 1 a.m. Sunday, he woke up to the sound of the snowcat starting and assumed the two missing men might have been stranded somewhere.

A family member of Wells responded to the lodge with a snowmobile and found tracks from the snowcat leading onto the ice of Island Lake, the sheriff’s office said.

The family member followed the tracks about 150 yards to the middle of the lake and found a large hole in the ice, indicating the snowcat had broken through.

Delta County Search and Rescue searched the lake and the shore for the missing men but found no evidence anyone walked away from the broken ice.

Colorado Search and Rescue sent resources in an attempt to confirm the snowcat was in the lake and to try to confirm the two men could be located.

The team was on the scene late Monday afternoon.