On a recent trip to Porters Creek, I was impressed by the number of 12 passenger vans parked at the trailhead (back to that in a bit). On the way, I pulled in at the portajohn at the picnic pavilion at which there were a number of horses and riders. As I was leaving, one of the younger guys said to another, "well, there was a sign." I thought nothing of it at the time. Then, hung on the closed trailhead gate was a nicely done wooden sign stating, "Trail Temporarily Closed to Horses." As I walked up the trail I saw a good many freshly (no butterflies yet) deposited horse piles (as we called them on the farm). Further up the trail, I encountered two large groups heading down the trail: one some very nice fellow "seasoned" citiizens, the other: friendly, college-age youth, many of whom were wearing red. I soon started back down also. When I arrived at the trailhead, the seniors were getting into vans marked "Jefferson County Hiking Club." The young people were getting into theirs, marked "University of Wisconsin Biology Department."
As I drove by the pavilion, the riders were still there, now joined by a Park Ranger... on the job.