wagons were the original off-road vehicles in their day since nearly all of the Emigrant Trails went cross country over rough, unimproved trails. The route over South Pass's main advantage for wagons pulled by oxen or mules was a shorter elevation over an "easy" pass to cross and its "easy" connection to nearby river valleys on both sides of the continental divide for water and grass. The emigrant trails were closed in winter. The North Platte–South Pass route was far less beneficial for a railroad, as it was about longer and much more expensive to construct up the narrow, steep and rocky canyons of the North Platte. The route along the North Platte was also further from Denver, Colorado, and went across difficult terrain, while a railroad connection to that City was already being planned for and surveyed. Efforts to survey a new, shorter, "better" route had been underway since 1864. By 1867, a new route was found and surveyed that went along part of the South Platte River in western Nebraska and after entering what is now the state of Wyoming, ascended a gradual sloping ridge between Lodgepole Creek and Crow Creek to the Evans pass (also called Sherman's Pass) which was discovered by the Union Pacific employed English surveyor and engineer, James Evans, in about 1864. This pass now is marked by the Ames Monument () marking its significance and commemorating two of the main backers of the Union Pacific Railroad. From North Platte, Nebraska (elevation ), the railroad proceeded westward and upward along a new path across the Nebraska Territory and Wyoming Territory (then part of the Dakota Territory) along the north bank of the South Platte River and into what would become the state of Wyoming at Lone Pine, Wyoming. Evans Pass was located between what would become the new "railroad" towns of Cheyenne and Laramie. Connecting to this pass, about west of Cheyenne, was the one place across the Laramie Mountains that had a narrow "guitar neck" of land that crossed the mountains without serious erosion at the so-called "gangplank" () discovered by Major General Grenville Dodge in 1865 when he was in the U.S. Army. The new route surveyed across Wyoming was over shorter, had a flatter profile, allowing for cheaper and easier railroad construction, and also went closer by Denver and the known coalfields in the Wasatch and Laramie Ranges. The railroad gained