A wildfire in Pikes Peak Colorado has burned more than 4,000 acres and displaced more than 11,000 people, as firefighters - backed by military cargo airplanes - continue to battle raging blazes throughout the state, officials said Tuesday. Fueled by dry conditions, high temperatures, and hot winds, the Waldo Canyon fire - located about 130 kilometers south of Denver - sent a cloud of smoke nearly 6,100 meters into the air over Colorado Springs near the foot of Pikes Peak, Reuters reported. According to the Denver Post, four C-130 military aircraft tankers were called in to help battle the blaze, dropping 3,000 gallons of fire retardant on the fire in shifts Monday afternoon. There are only eight such airplanes in use in the United States. More than 11,000 residents were evacuated, though more than half of them were allowed to return to their homes late Monday, leaving 4,800 displaced west of Colorado Springs. To this point, no deaths or injuries have been reported, fire officials said, but firefighters have managed to contain just 5 percent of the fire's perimeter. The cause of the fire is under investigation.