Soper's Mill/Bear Creek Acess is mostly singletrack with a few rocks, roots, and log crossings.
How to get there:
The simplest way to get there is by using the trail access behind the southbound I-35 rest stop just south of Story City and head for the woods once there. http://www.storycounty.com/adx/aspx/adxGetMedia.aspx?DocID=404,390,15,6,1,Documents&MediaID=354&Filename=skunk_river_greenbelt.pdf
This would be a fun place to stop if you happen to be coming down I-35 and/or live in Story County