John Mullan's celebrated road, a 625-mile link that connected the Missouri and Columbia rivers and eventually became a significant component of Interstate 90, established the West Point graduate as an accomplished engineer. After completing the West's first highway, he lived for nearly another half century, a period of dynamic change.
 
Idaho State Historian Keith Petersen takes a fresh look at the dashing young soldier/explorer--probing his complex personality and continuing a story that includes business partnerships and personal relationships with some of the West's most intriguing characters.