Road for wagons ????

While in Kansas several weeks ago I noticed a strange "formation" for lack of a better explanation.
There was a raised "road" of sorts running through the plains. It was in the West side of the highway and obviously hadn't been traveled on for decades. It was still there though sticking out for all to see. Trees had sprouted on the North and South sides of it and it ran until it was out of sight. I wish I could hear the stories it could tell from the beginning. It would surely be the true history of settling the area.

Once again, click on the image and it will enlarge.