Better mapping has led Yellowstone National Park officials to scale back their estimate of the size of the "LeHardy Fire" to just about 500 acres. However, the Grand Loop Road north of Fishing Bridge remains closed because of the blaze.

Sparks from a downed powerline are the suspected cause of the fire, which started Wednesday afternoon near LeHardy Rapids along the park’s Grand Loop Road three miles north of Fishing Bridge.

The fire started in a powerline corridor which runs west of the road. Gusty southwest winds cause the fire to move east, first jumping the road and then jumping the Yellowstone River. That prompted temporary closure of the road between Fishing Bridge Junction and Mud Volcano, which is south of Canyon Junction. The fire also cut electrical service to the Fishing Bridge and Lake area, which are currently running on a large generator.

Thursday’s firefighting efforts were focused on the west side of the Yellowstone River. Morning retardant drops from large air tankers and afternoon water drops from helicopters aided hand crews who spent the day constructing a control line along the fire’s west flank. The goal is to contain the fire on the west bank of the Yellowstone River in order to reopen the road to visitor travel and restore commercial power. About 140 people are assigned to the LeHardy Fire, up from 67 on Wednesday night.

Today's weather forecast again calls for temperatures in the 70s, with gusty afternoon winds out of the southwest.

It’s unknown when the road between Fishing Bridge and Mud Volcano will reopen to travel. Updated Yellowstone National Park road information is available 24 hours a day by calling 307-344-2117. Some backcountry trails and campsites are also impacted by the fire. Updated information is available at all of the park’s Backcountry Offices or by calling 307-344-2160 during business hours.

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/fir forest. All park entrances and all seasonal visitor services are open. This is the third fire in Yellowstone National Park this season. The other fires were just one-tenth of an acre in size each.