The Arnica Fire in Yellowstone National Park, now impacting 8,300 acres, keeps expanding and forced the closure of the Grand Loop Road between the junction at Fishing Bridge and West Thumb overnight.

National Park Service officials hope to reopen the road today, if conditions permit. The issue is now one of safety: the fire has reached the road, and generating enough smoke to impact visibility. In addition, the smoke is now thick enough to lead Park officials to warn those with immune-system issues or heart and lung conditions to avoid the area. The fire is located two miles northwest of Bridge Bay with small spot fires within one mile of Bridge Bay.

The closure is a most inconvenient one for Park visitors. Because the Norris to Madison portion of the Grand Loop Road is closed, the only open route between the north and south portions of the Park is through the area impacted by the fire. 

Crews will be out today to remove snags from the side of the road, with the goal of reopening for traffic soon. Still, with given the fact that there's no measurable precipitation forecast for the area until Wednesday, when rain and snow are possible, visitors and residents are in for a few days of not knowing precisely whether the road will be open.

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