Dozens of homes destroyed near by Colorado fire.
Crews are struggling to contain a quickly moving wildfire burning near Boulder, Colorado.
The blaze has already consumed more than 3,500 acres and destroyed dozens of homes.
Efforts have been hampered by the weather.
High winds kept planes on the ground for much of the day Monday.
Tuesday had its own problems.
"We've had weather inversion over the fire which has held the smoke close to the ground," explained Boulder County Sheriff Department Commander Rick Brough.
The blaze broke out Monday morning in Four Mile Canyon northwest of Boulder.
45 mile per hour wind gusts quickly sent flames roaring through the foothills, forcing more than 3,000 people from their homes in the canyons and surrounding areas.
Ground crews face a difficult and dangerous fight due to the rugged, steep terrain.
More than 35 agencies have responded to the fire.
State and federal help is also on the way.
Tankers, spotting planes and helicopters are prepared to make runs as soon as the smoke shifts.
Despite the fires quick advance, no injuries have been reported.
It's still not clear when the fire will be contained.