Another Colorado wildfire forced hundreds to flee their homes Monday. (Associated Press)

Hundreds of people were out of their homes Monday after another wildfire broke out and quickly spread in the foothills near Loveland in northern Colorado.

Meanwhile, authorities in Colorado said another fire, which destroyed at least 166 homes. was most likely sparked by a fire pit. Boulder County sheriff's Cmdr. Rick Brough said Monday that a homeowner made a fire in the pit days before the wildfire broke out and doused it with water and stirred the ashes to put it out.

Investigators believe gusty winds Sept. 6 reignited the embers and blew them out of the fire pit, starting the wildfire that turned into one of the worst in the state's history. Authorities haven't decided whether the owner will face criminal charges.

More residents who lost homes in that fire were able to return to see the damage Monday. About 300 firefighters were fighting the other wildfire about 56 kilometres away near Loveland.

The fire near Loveland destroyed one home. Merlin Green, the division chief for Loveland Fire and Rescue, said firefighters were fortunate that the tankers and other resources used to fight the first fire, which was among the worst in the western state's history, were available.

"It certainly could have been a lot worse," said Green, who hoped those tankers would once again be able to drop fire retardant on the blaze Monday.

The fire also destroyed four outbuildings and a recreational vehicle, but no injuries have been reported. The blaze was 10 per cent contained by Monday morning, officials said.

A greyish haze hung over the city, partially obscuring the view of the foothills.