A lightning-caused fire is burning southeast of Williams near Colcord Canyon. Kaibab National Forest officials say the Thumb Flat Fire is burning about 18 miles southeast of Williams and has burned 475 acres. Fire managers say the fire is in open country and is being allowed to burn naturally within a pre-determined management area to reduce fuel loads and promote healthier landscapes. The fire strategy is to contain the fire within a road system surrounding the area. Officials say the fire was started by a lightning streak at around midnight last Thursday.