BRADLEYVILLE, Mo. — Fire crews are working to contain a fire that has burned about 300 acres of the Mark Twain National Forest in southern Missouri.

U.S. Forest Service spokesman Bill Paxton says a patrol discovered smoke Monday in a 12,000-acre area known as the Hercules Glades Wilderness. The patrol had been roving the area in Taney County because dry conditions had put it at risk for fire. Paxton said Thursday that the 35 firefighters battling the blaze are “making real good progress” and that rains that fell Wednesday helped.

Containment lines have been established on the east and north ends of the fire and part of the southwest flank.

Paxton says no structures are threatened.

The Mark Twain National Forest spans 1.5 million acres in 29 counties in southern and central Missouri.