By mid-September 2010, the Fourmile Canyon Fire had burned more than 6,000 acres (2,500 hectares), leaving behind a charred landscape west of Boulder, Colorado. The fire started on September 6, 2010, and burned an area about 5 miles (8 kilometers) west of downtown Boulder. Besides consuming dozens of homes, the fire sent thick smoke over the city, prompting public health alerts.
The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image of the Fourmile Canyon burn scar on September 16, 2010. Sunlight brightens south-facing slopes while leaving north-facing slopes in shadow. Outside of the burned area, the foothills west of Boulder present a patchwork of beige ground and dark green vegetation. Within the burned area, charcoal gray predominates. On its northern side, the burn scar grazes the city of Gold Hill. The scar extends southward and eastward over the hills and valleys west of Boulder, crossing the highway in the Boulder Canyon south of Gold Hill.
By mid- September 2010, 13 counties and one American Indian reservation in Colorado imposed fire bans. Citing wildfires and dry conditions, authorities enacted the first wide-range fire ban in two years.
NASA Earth Observatory image created by Jesse Allen and Robert Simmon, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Caption by Michon Scott.