John Mullan, Jr. (July 31, 1830 – December 28, 1909) was an American soldier, explorer, civil servant, and road builder, heled the construction crew which built which road, was the first wagon road to cross the Rocky Mountains to the Inland of the Pacific Northwest, in Montana, Idaho, and Washington state, between the spring of 1859 and summer 1860?  
John Mullan (road builder):  He extensively explored western Montana and portions of southeastern Idaho, discovered Mullan Pass, participated in the Coeur d'Alene War, and led the construction crew which built the Mullan Road in Montana, Idaho, and Washington state between the spring of 1859 and summer of 1860.
i don't know