I rode about 40 miles on the Sparta-Elroy trail several years ago. The trail is crushed limestone but more like a dirt road in places. The trail was very wet (and dark) in the tunnels. I would have brought a light if I had known better.

We were staying in Sparta for the week, doing loop rides on local roads each day. We road the trail one day to stretch out a metric century to 100 miles. The best part was the pie shop, which I think is called "P R Squared." Make sure you stop there.

I just got back from riding in Wisconsin last week. We rode another rail trail from New Glaris to Broadhead. Wisconsin has a very nice network of rails-2-trails.