“Pick a Park” series. Wetland and River Loop Trails. about 3.0 miles rated moderate. The trail follows the Duck River and at 1.35 miles, there is a 20-foot observation tower overlooking a native grass field and wetland. The Wetland Trail connects to the River Loop Trail. For more information or to sign up, contact Jeanne Conatser at 615-971-8894 or firstname.lastname@example.org.