The Trail Creek Fire burning approximately 20 miles west of Wisdom has grown to 19,848 acres with no containment as of Sunday morning, according to InciWeb.
Fire activity is expected to increase in all directions and threaten the Highway 43 corridor over the next 72 hours. Highway 43 is intermittently open and closed from the Montana/Idaho border to 18 miles west of Wisdom. Travelers and the public can check current conditions on the Montana Department of Transportation Road Report.
Most fire growth continues to be towards the east and southeast, and crews are working to protect structures along the Highway 43 corridor on the east side of the fire, particularly around the Big Hole National Battlefield and private property south of the highway. A structure protection plan will be required for several private residences near the Big Hole Battlefield.
Crews on the west side of the fire are focused on preventing it from crossing the Continental Divide.
On Saturday, officials issued a closure order for the Big Hole National Battlefield until further notice.
Officials say the fire will be a long-term event that will burn through the fire season until a season-ending event produces moisture.
The lightning-caused Trail Creek Fire was first spotted on July 8. There is currently a total of 147 personnel assigned to the fire.