MICHAEL CAST Like a kid in a candy store, U.S. Rep. Matt Rosendale toured the Montana Resources mine in Butte Friday. âWhen do I push the plunger?â said the Republican congressman, a reference to blowing the dynamite in the pit. In his first ever tour of the mine, Rosendale saw the active Continental Pit, the shovel and haul trucks operating at full steam, and the mill. He didnât make it to the Berkeley Pit on this trip. Rosendale inquired about ore grade, and asked how it compared to the proposed Black Butte mine. Black Butte is a controversial underground copper mining project near White Sulphur Springs. Critics are deeply concerned the mine could affect the Smith River, and Rosendale is an adamant supporter of the project.