Which  county located in the U.S. state of Montana is Brockton  a town in
Brockton, Montana Brockton is a town in Roosevelt County, Montana, United States. The population was 255 at the 2010 census.
Montana Highway 13 Montana Highway 13 (MT 13) is a 112 mi state highway in the east of the U.S. state of Montana. The highway begins at its southern end at MT 200 and connects the three county seats of McCone, Roosevelt and Daniels counties. It also provides access across the northern international border into Saskatchewan, towards Moose Jaw, at the Port of Scobey.