Wisconsin's Cattail State Trail runs for nearly 18 miles on an old Soo Line rail line between Amery and Almena with access in Turtle Lake. A good spot to start the hike is in Amery at the Trailhead Pavilion in Soo Lake Park (below; photo courtesy City of Amery) Parking, restrooms and wifi access is available there.
Heading east from the pavilion, the trail crosses a bridge over the Apple River (below).
The trail is flat and wide as it leaves Amery (below).
Here's a full description of the trail.
Read more about day hiking this and nearby trails in my Hittin’ the Trail: Day Polk County, Wisconsin guidebook.