A wildfire dubbed the Wall Fire broke out 25 miles southwest of Ashland over the weekend.
The Montana Department of Natural Resources & Conservation reported that the fire has grown to 1,535 acres, and it is 40% contained.
It was initially spotted Saturday shortly before 12:48 p.m. from a lookout tower.
"Firefighters from Rosebud County, Powder River County, BLM and US Forest Service were immediately dispatched for initial attack," the report stated. "The fire started on private land and moved to BLM. Steep terrain and thick Juniper trees accelerated fire growth on Saturday and Sunday."
A full suppression strategy of the fire has been implemented, but has potential to spread southeast and northeast.
The fire burned throughout the evening on Saturday and into the early morning.
The vegetation is primarily Juniper with mixed Ponderosa, grass, and brush, the report said.
Current resources on the fire include more than 90 people, 13 engines, one water tender, three dozers, two Hotshot crews, one Type II Initial Attack crew, and two helicopters.
More resources have been ordered and should arrive Monday. Air support is available out of Miles City and Billings if needed.