GRAND JUNCTION, Colo. (NewsNation) — A wildfire burning since late July in Colorado has become the state’s largest wildfire in history, NewsNation affiliate KDVR reports.

The fire has scorched more than 139,000 acres. It’s burning about 18 miles north of Grand Junction in Mesa and Garfield counties. It started July 31 and was caused by lightning.

Previously, the Hayman Fire was Colorado’s largest wildfire. For six weeks in 2002, that fire burned 138,000 acres of forest land southwest of Denver, destroying 133 homes.

As of Thursday evening, the Pine Gulch fire was 77% contained, and more than 900 people were fighting the fire.