A wildfire that tore through the rough-hewn foothills of Colorado has destroyed dozens of houses and forcing hundreds to evacuate their homes, authorities said Tuesday.

Some residents narrowly escaped, but no injuries have been reported.

The blaze broke out Monday morning northwest of Boulder and quickly spread across 3,500 square acres.
    
Authorities say 1,000 homes had to be evacuated from the canyon and surrounding areas.

"Approximately 3,000 residents are in the evacuation areas," Boulder's emergency management office said. "The Four Mile Canyon Fire is a wind-driven fire burning in steep, rocky, and hard to access terrain west and north of the City of Boulder."

It's unknown what caused the fire, and officials said it was too early to say how much of the blaze has been contained.