The Neal Smith Trail starts in Des Moines and ends at Big Creek State Park in Polk City.  We parked at the Saylorville Lake Visitor Center and rode north to Red Feather Prairie, where the trail is currently closed.  Round-trip, it was a total of 5 miles which my kids said felt longer due to the hills on the trail.

My favorite part was stopping at the butterfly garden, which is right along the trail.  August is a great time to visit the garden.  There are many shaded benches along the trail which my kiddo who has chronic lung disease appreciated.  He's a trooper, but needs to take frequent breaks.

My other son has autism and was having sensory struggles with his helmet, so you'll see he's not wearing a helmet in the last photo.  It wasn't ideal and I definitely don't recommend having your kids ride without a helmet.