The Mullan Road was carved into the face of the mountains high above the Clark Fork River west of here after Lieutenant John Mullan, seeking to keep his wagon road as close to the river as possible, was forced to find an alternate route when a mountain spur reached all the way to the river’s edge. Calling the six-mile cut through rocky spurs an undertaking he almost feared to attempt, Mullan assembled his entire work force of 150 citizens and soldiers on May 10, 1860, at the west side of the spur. Over the next six weeks, the men dug, whittled, and blasted their way up the mountainside to an altitude of a thousand feet above the river. A premature explosion while clearing a path through the rocks wounded one man and severely stunned another. Completed in June 1860, the Big Side Cut was the most awe-inspiring segment of the entire 624-mile Mullan Road, and in 1862 a traveler called it a narrow wagon track that left no room for careless or uncertain driving.