John Mullan's celebrated road - a 625-mile link that connected the Missouri and Columbia Rivers - established the West Point graduate as an accomplished engineer. After completing the Northwest's first engineered highway at age thirty-two, he lived for nearly another half century, a period of dynamic change. When he died in 1909, automobiles were making their initial crossings along his route. The arterial eventually became a critical link in America's longest interstate freeway, I-90. Yet despite frequent mentions in books about the nineteenth century Northwest, the soldier/explorer has remained little more than a caricature: a dashing young Army officer who comes West, builds one of its most important thoroughfares, and then disappears from regional literature. Now, in lively prose, Idaho State Historian Keith Petersen takes a fresh look at Mullan, whose road significantly impacted the development of the Northwest. Mullan's story includes business partnerships and personal relationships with some of the West's most intriguing characters: Father Pierre-Jean DeSmet, General William T. Sherman, Chico founder John Bidwell, Idaho gold discoverer Elias Pierce, Yakama Indian chief Owhi, and others. The first comprehensive portrayal of John Mullan's life, this deeply researched biography probes the explorer's complex personality, his rise to fame, and his fall from grace.