A wildfire in the backcountry of Yellowstone National Park has nearly doubled in size, to 2,119 acres, in the past 24 hours, but it doesn't pose a threat to visitors or park structures or roads.

The Spruce Fire, sparked by a lightning strike on September 4, was burning  Monday in a lodgepole forest about 10 miles west of Fishing Bridge and a couple miles south of the Hayden Valley. A streaming plume of smoke could be seen from the West Thumb area to the south and from Mount Washburn to the north.

Park officials say the fire "continues to play its natural role in the ecosystem and crews are managing it for its benefits to park resources. It is burning in a typical mosaic pattern within the fire’s perimeter, with overall fire activity picking up in the afternoon as temperatures rise, relative humidity levels drop, and gusty winds increase."

The decision on managing each fire in the park is based on a number of factors, including current and predicted conditions, as well as potential values at risk. There have been two additional park fires that have been suppressed in the past week, a human-caused fire in Mammoth Hot Springs on September 10, and a lightning-caused fire near the northwest boundary of the park on September 12.

The fire danger in Yellowstone National Park is currently “high.” There are no fire restrictions in place, however, campfires are only allowed in designated grills in park campgrounds, some picnic areas, and specific backcountry campsites.