Lex Anteinternet: The Oregon Trail in Converse County.:
Above is an Oregon Trail marker, placed in 1913, south of Douglas Wyoming. The Oregon Trail itself is visible directly behind it, being the strip of green sagebrush that's grown up over it in the prairie.
The white marker on the top of the hill is a marker used to mark the course of the trail.
Erosion in the path of the trail.