Sunset in South Pass, the most-traveled and most-trusted low valley -- two nearby valleys, actually -- through the fearsome Rocky Mountains for 19th-Century westward emigrants on the Oregon, Mormon, and California trails -- which followed much the same route to this point and beyond before diverging -- as well as Pony Express riders.
Original image from Carol M. Highsmith’s America, Library of Congress collection. Digitally enhanced by rawpixel.