Gusting winds have fueled a rapid increase in the size of the "LeHardy Fire" in Yellowstone National Park.

The fire, which was reported to range in size from 5 to 10 acres at 4 p.m. Wednesday afternoon, grew to roughly 600 acres by nightfall. Actively burning near the Grand Loop Road some 3 miles north of Fishing Bridge, the fire has prompted park officials to keep that stretch of road between Fishing Bridge and Mud Volcano closed for the immediate future.

The fire was started along a powerline that parallels the road. Gusty southwest winds quickly pushed the fire east across the road and "spotting" of embers enabled the blaze to leap the Yellowstone River.

Yellowstone National Park firefighters, West Yellowstone smokejumpers, two Type 1 air tankers from Billings, two helicopters, and fire engines from several surrounding areas are already assigned to the fire. Additional firefighting resources including two Type I hand crews are on order and are expected to arrive overnight and into the morning.

Today's weather forecast calls for temperatures in the 70s, with humidity between 17 and 23 percent and afternoon winds from the southwest at 10 to 15 miles an hour with gusts to 25 miles and hour.

Currently, the LeHardy Fire does not pose a threat to visitors. It is burning to the northeast away from roads and developed areas in a mature lodgepole and spruce forest. All park entrances and all seasonal visitor services are open.