CHEYENNE, Wyo. -

A wildfire in the heart of Yellowstone National Park has forced a temporary closure of a 7.5-mile section of the Grand Loop Road.

The road is closed from Fishing Bridge Junction to the north to the Elk Antler Creek pullout in the south end of Hayden Valley.

Meantime, more firefighters are arriving to bolster defenses against the Alum Fire.

While four other fires in the park are in remote areas, the Alum Fire is close enough to facilities along the northwest shore of Yellowstone Lake to cause some concern.

About 150 firefighters and equipment are being positioned in the Lake, Fishing Bridge and Bridge Bay areas in case the fire threatens those areas.

Started by lightning last week, the fire has burned about seven square miles.