DENVER -- A 2,500-acre grass fire that burned in the Wiggins area Monday was completely contained about six hours later.

Margie Martinez of the Weld County Sheriff's Office said the fire started around 12:20 p.m. Conditions in the area were hot and dry, with winds gusting at times.

Martinez said it's not clear how the fire started. The blaze burned mostly grass and ranch land west of Wiggins near Interstate 76.

By late afternoon, fire crews moved ahead of the fire to the west and used a process called back burning.

"That's where they start a fire on an edge and when the fire meets up, it has no where to go," Martinez said.

AirTracker7 showed several small sheds near the fire line. However, no major structures were threatened.

"We've had a horrible, horrible dry year," said Ron Kembel, who watched the fire while he was camping from nearby Empire Reservior.

Six fire departments and an air tanker worked to battle the blaze, which was extinguished by 6:20 p.m.