Platte River State Park Trails   Lots of elevation changes, surprisingly.  Some parts are pretty demanding.  It's easy to keep your head down, as you are breathing heavy and looking for sure footing, but try to keep your head up or you will miss a lot of wildlife.  Trails are not marked well, but all trails eventually loop back to the main horse trail.  Very little wind in the valleys, so in the thick of summer, it is humid as hell, and mosquitoes are brutal.  Use a lot of bug spray, or better     yet, hike in May or October.  Go on a weekday, and you will find yourself miles from civilization, and alone with your group.  There is a complete canopy of mature trees along a vast majority of the feeder trails.  One last thing, it is easily the hilliest trail in Eastern Nebraska. Says David Weidner The trails starting at the tower are no longer suitable for foot traffic and have been ruined by mountain biking - greatly widened and very dirty. You are also in physical danger as bikers will suddenly appear over steep blind spots with reckless abandon. Says Richard Van Cura