The Chicago Great Western Railroad once ran on this old rail line. After merging into the Chicago & Northwestern Railroad in 1968, the route here was abandoned. Now, the right of way is being converted to a hiking and biking trail called the Prairie Land Trail. The surface is now a smoother pressed limestone gravel type surface, so bring the bicycles and go for a ride. Bring water and sunscreen as there isn't a lot of shade.
You may get to see a variety of wildlife out here.
The cache? It is a small pill bottle containing a log. I don't remember if there is a small pencil inside or not, so be sure to bring your own for signing the log.
Enjoy your time out here.