Lombard Ferry Crossing on the Oregon Trail in Wyoming. The Green River presented a major obstacle to the westward bound emigrants. Throughout the years of the emigration, a number of different locations were used to ford, float, or ferry over the rivers. However, the most popular means of crossing for those on the main branch of the westward emigrant trails was the "Lombard Ferry," established by mountain men in 1843. Photo by the Bureau of Land Management.