Tunnel of Mauve.
One of the things that impressed me most as I travelled West to relocate from Michigan to Washington state was the sheer determination and amount of work required to carve highways from one side of the country to the other. From cutting through mountain ranges, to passing over massively large bodies of water, to tunneling under both—literally nothing stood in the way of American mobility.
Green River, Wyoming, was one of the few towns along the Union Pacific that existed before the railroad arrived. This twin tunnel doesn't actually go under the river, it cuts through a butte overlooking the river.
I'm getting caught up on old photos. This shot was taken outside Green River, Wyoming, on Monday, April 1, 2013.