Though many fires in the Uinta-Wasatch-Cache National Forest are still active, only the Peterson Hollow Fire required "significant suppression efforts" Thursday. In contrast, firefighters have been managing the four other wildfires and allowing them to "perform their natural role in controlling fuel build-up and rejuvenating vegetation," according to news releases from the U.S. Forest Service. The 1,121-acre Peterson Hollow Fire, which began Sunday just north of Beaver Mountain Ski Resort, grew about 50 acres from Wednesday to Thursday, according to releases. It was 10 percent contained Thursday, authorities said. Crews of 220 firefighters, three air tankers and three helicopters fought the fire Wednesday and Thursday, releases said. Limited road access has increased the need for aerial support for fire suppression and supply drops to crews, releases said.