Authorities have found a second body in the debris of a burned-out home in Colorado Springs, marking the second death from a fierce wildfire that ranks as Colorado's most destructive on record after incinerating 347 homes.

Police Chief Peter Carey released no further details about the victim, who becomes the sixth person killed this year in a Colorado wildfire season described by the governor as the worst in the state's history.

The first fatality was confirmed on Thursday, although no details of the victim have been released.

Earlier this week, police said some people listed as unaccounted for were believed to have neglected to register with the city or the American Red Cross as evacuees.

The discovery of the second body came on the same day that President Barack Obama visited the affected area.

Before landing, Air Force One flew over part of the Rocky Mountains where smoke could be seen rising from the areas ravaged by the blaze, which has been fuelled by scorching heat, high winds and bone-dry conditions.

Lighter winds have been helping firefighters make progress, but on Friday afternoon, the fire remained just 15 per cent contained.