Update 7:40 p.m. The Pony Creek fire has grown to 1,000 acres near Colstrip.
Montana wildland firefighters are currently working to contain several large fire starts Wednesday in the southeastern part of the state.
The Pony Creek Fire, which sparked in Rosebud County around 11:28 a.m., has already burned at least 600 acres as of 6 p.m.
The Rosebud County Sheriff's Office tells MTN that city and county fire services are tackling the blaze, and the Montana Department of Natural Resources and Conservation has been notified.
That fire is burning north of Colstrip and it is unclear if it is contained at all.
Meanwhile, the Summer Springs Fire is burning in Treasure County and has scorched at least 250 acres.
In addition, the Mission Butte Fire has burned about 500 acres Wednesday east of St. Xavier on the Crow reservation.
Click here for updates on fires at MT Fire Info, the state's fire database.
