Meramec River Loop via Stinging Nettle Trail and Al Foster Trail

based on 5 tracks & routes
5.7 mi
3 hrs 25 min
108 ft
Elev Gain


This is an easy loop trail that begins in Sherman Beach County Park, passes into Castlewood State Park, and ends back at Sherman Beach (since it it a loop). The whole loop is about 5 miles long, but there are several short connectors that can make this hike shorter if you’re pressed for time. This area of St. Louis County is a patchwork of various State, County, and Municipal Parks on both banks of the Meramec River. Signs indicate when you leave one park and enter another, but the paths are unhindered and allow for longer hikes. This area is used by mountain bikers and trail runners in addition to hikers.

You begin the loop counterclockwise by taking the Stinging Nettle Trail from the Sherman Beach parking lot. The Stinging Nettle Trail travels along the north bank of the Meramec River. This trail is flat and packed earth since it is in the river bottom. Some parts of the trail are loose sand. After heavy rains, the Meramec River can flood in this area, so check local conditions before hiking this trail. The path is nice and wide so you are unlikely to get “stung” in a patch of Stinging Nettle unless you go off-trail. The Stinging Nettle plant is covered with protective spines that resemble tiny hypodermic needles. These can inject histamine on unprotected skin that can cause an intensely itchy rash.

The Stinging Nettle Trail eventually intersects the Al Foster Trail in the western portion of Castlewood State Park. Al Foster was a noted nature journalist and photographer. A connector trail can bring you to the more popular eastern section of Castlewood, but to complete this loop, you will return on the Al Foster Trail. This packed earth trail follows the old Pacific Railroad bed (built in 1854), so it is flat and easy to hike. This loop ends back in the Sherman Beach parking lot, but the Al Foster Trail continues another 3.5 miles to the small town of Glencoe.

Tall sycamore and cottonwood trees make up the forest. Songbirds are abundant in the woods, and you can likely see waterfowl in or near the Meramec River.

Getting Started

Follow St. Paul Road in Ballwin, Missouri to get to the Sherman Beach parking lot.

Part of the trail is in Castlewood State Park, but not the main portion of the park. There is not a direct road between these two parts of the park.

There was significant road construction at a railroad crossing just outside of the park in July 2023. This required a detour on a makeshift dirt road to get to the park. The Stinging Nettle trailhead is at the southeast corner of the parking lot. You will return to the lot at its northeast corner along the Al Foster Trail.

Taking Children

This is a good trail for kids. It is easy to travel since it is not too rocky or steep. The whole loop might be a bit long for little legs, but the loop can be shortened with the connector trails.

    Rate this Hike

Public Tracks