Ghostly Encounter?

From: Anonymous 
Story type: Ghost
Location: Pulaski, WI
Source: Form Submission

This all started yesterday. I had decided to go on a trail ride with my horse, and this is the first time we had done it alone. Crossing a field, we made our way down a trail which lead to what I knew was an abandoned railroad bridge (the entire trail was a railroad track, converted into a public access trail). The trail is wooded on both sides, and it was quite pleasant, so I stopped my horse, and we stood for several moments. I happened to glance to the left, and as I did, I heard a thumping sound, as though someone were crossing the bridge. At that moment (even though I didn't tense up) my horse began to get extremely skittish. He laid his ears back and started trying to turn around and run the opposite direction. Needless to say, we got out of there pretty quickly, and he was fine for the rest of the ride.