The trail made a final crossing of the Sweetwater River (one of the three mandatory crossings that could not be avoided by alternate routes) shortly before reaching South Pass. This crossing became an outpost known as Upper Sweetwater Station or South Pass Station. It was the site of a Pony Express station, and even housed a military guard unit (to protect emigrants against Indian attacks) between 1862 and 1868. After the station was abandoned in 1868 it was burned down by Indians, giving it a new name of "Burnt Ranch".

Today the site sits on private ranch land, and permission of the landownder should be obtained before visiting.