A West Point graduate, Lieutenant John Mullan heads to the frontier in the early 1850s to help survey an important wagon road and eventual railway route through the Northern Rockies and the Pacific Northwest. During a series of explorations in the mountains of what is now Montana and Idaho, Mullan’s leadership skills are tested when his men confront a variety of perils under the harsh frontier conditions. Mullan returns to the far west in 1858 and is about to finally begin construction on the important government road when hostilities erupt with the Yakima and other tribes along the Columbia River in Washington. Now, instead of building a wagon road, Mullan is suddenly placed in command of a platoon of Nez Perce scouts who he must lead into battle. During a desperate fight against the Yakima, Mullan’s future and the fate of the Northwest may depend on the young officer and his scouts.