The Mullan Road climbed Helena Hill from Fort Benton and extended more than 600 miles to the head of navigation on the Columbia River at Fort Walla Walla. As the first federal highway in the Northwest, it carried covered wagons, stagecoaches, and freighters bound for the gold bonanzas in the mountains of Montana and Idaho. Branch roads led to Helena, Bannack, and Virginia City, while the main road continued west through Missoula and up the Clark's Fork to Spokane before turning south through the Palouse to the Columbia.