Black River Riparian Forest

Location: Renton.

Length: About a half-mile each way; grassy trail connects to the south with a paved pedestrian/bike path.

Level of difficulty: Level to gentle.

Setting: These wetlands are one of the last protected lowland, deciduous, riparian forests remaining in Puget Sound. The site marks the remains of the vanished Black River, which once flowed out of Lake Washington south into the Duwamish River. With the completion of the ship canal in 1917, the lake level was lowered almost 9 feet, cutting off the river's outlet.

Highlights: This 93-acre refuge harbors many animals, including a unique subspecies of great blue heron, which does not migrate and exists only in Puget Sound and in the Fraser River Valley (near Vancouver, B.C.). Large cottonwood trees host the largest heron colony in Washington, with approximately 130 nests this year.

Nesting activity begins in late winter, and the fledglings from this year should be around for a few more weeks. The herons are often threatened by eagles and by proposed development on the hill behind their nests.

To see the herons, you will need binoculars; from the parking lot, follow the dirt trail into the forest, turn right at the water's edge, and walk to where a break in the shrubs reveals tall cottonwoods across the water. Continue along this path to reach a paved trail that leads south along the wetlands to Southwest Grady Way.

Facilities: None.

Restrictions: Leash and scoop laws in effect. Be quiet and do not try to get close to the herons. In this secluded urban area, if you must go alone, stay alert.

Directions: From eastbound Interstate 405, take Exit 1, turn left off the exit ramp onto West Valley Highway, cross under I-405, and turn right on Southwest Grady Way. From westbound 405, take Exit 1, turn right off the exit ramp on Interurban Avenue, and turn right at the next light onto Southwest Grady Way. In .6 mile, turn left on Oakesdale Avenue Southwest, and in another .6 mile, park on the right at Monster Road Southwest at the small pullout marked "Black River Riparian Forest."

Bus: Metro Route 163 passes near the south end of the trail. 206-553-3000 or transit.metrokc.gov.

Information: 206-933-0222 or www.heronsforever.org.

Cathy McDonald, a Renton-based freelance writer, is a regular contributor to Northwest Weekend.