Overview
Mercer Slough Nature Park is one of the largest remaining wetlands on the eastern shore of Lake Washington, sitting within the city of Bellevue, Washington. Covering roughly 320 acres, it is a rare example of functioning urban wetland habitat, where a working blueberry farm and miles of natural trails coexist inside a major metropolitan area.
The park is managed by the City of Bellevue and centers on the Mercer Slough, a slow-moving waterway that drains into Lake Washington. Visitors will find a mix of open water, emergent marsh, willow scrub, and mature cottonwood forest — an unusually diverse set of habitats for a city park.
The Winters House, a historic farmstead near the park's main entrance on Bellevue Way SE, serves as an environmental education center operated by Eastside Audubon and affiliated organizations. It is a good first stop for maps, interpretive information, and details on seasonal programs.
The park attracts birdwatchers, trail runners, canoeists, and families looking for easy nature access without leaving the urban core. Because it is free to enter and well-maintained, it draws a consistent year-round audience of local residents and visiting nature enthusiasts alike.
Getting There
Mercer Slough Nature Park has several access points within Bellevue. The primary visitor entry and parking area is located near the Winters House on Bellevue Way SE, just south of the SE 8th Street intersection. A second parking area and canoe launch is located off SE 8th Street closer to I-405.
By car: The park is straightforward to reach from I-405 via the SE 8th Street exit. Street parking and a small dedicated lot are available near the Winters House; the lot fills on warm weekend afternoons, so arriving earlier in the day is advisable.
By public transit: King County Metro serves the Bellevue Way SE corridor. Several bus routes connect downtown Bellevue (Bellevue Transit Center) to stops within walking distance of the park entrances. Verify current route numbers and stop locations on the King County Metro trip planner (metro.kingcounty.gov), as schedules change periodically.
On foot or by bike: The park connects to the regional trail network. Cyclists and pedestrians can reach it via the Bellevue Trail system and connections to the Mountains to Sound Greenway. The Bellevue Way SE frontage has sidewalks.
Getting Around
The park is best explored on foot. Trail surfaces vary: the main loops near the Winters House are paved or packed gravel and are accessible for most visitors; the inner marsh trails can be uneven and wet, especially from November through March.
Bring a printed or downloaded trail map — cell signal is adequate in most areas but the park's dense vegetation can interfere with GPS accuracy in places. Maps are available at the Winters House when it is staffed and on the City of Bellevue Parks website.
Dogs are welcome on leash. Keep dogs on trails and away from the boardwalk edges to protect nesting birds and wetland vegetation.
Things to See & Do
Trails and Boardwalks
The park contains approximately 7 miles of interconnected trails, ranging from paved paths accessible to strollers and wheelchairs to soft-surface dirt tracks through denser vegetation. The signature feature is a series of wooden boardwalks that carry walkers directly over the slough and marshland, offering close-up views of aquatic plants, turtles, and waterfowl at eye level.
- Bellefields Loop Trail: A popular, relatively flat loop that passes through cottonwood forest and wetland edges.
- Heritage Trail: Connects to the blueberry farm and interpretive signage about the area's agricultural past.
- Swamp Trail / East Channel Trail: Quieter routes deeper into the marsh; muddy conditions possible in wet seasons.
Blueberry Farm
Shamrock Farm, operating within the park boundaries, is one of the few remaining working farms inside Bellevue city limits. U-pick blueberry sessions are typically available in summer; verify current availability and hours directly with the City of Bellevue Parks department or on-site signage before visiting.
Birdwatching
The slough is a productive birding site throughout the year. Common sightings include great blue heron, osprey, belted kingfisher, marsh wren, and a variety of dabbling ducks. The Eastside Audubon Society occasionally leads guided bird walks departing from the Winters House; check their website for current schedules.
Paddling
Non-motorized watercraft — canoes and kayaks — can be launched at the SE 8th Street access point. Paddling north through the slough toward Lake Washington offers a quiet, low-traffic water route. Carry-in launch only; no rentals are available within the park itself.
Environmental Education
The Winters House Environmental Learning Center hosts school groups, community programs, and informal drop-in education. The building and its grounds include interpretive displays about wetland ecology and the history of farming in the slough valley.
Practical Information
Entry fee: The park is free and open to the public. Verify current hours on the City of Bellevue Parks website, as gate or lot access times may vary seasonally.
Restrooms: Portable or permanent restroom facilities are located near the Winters House parking area. Confirm availability on arrival, particularly outside peak season.
Weather: Bellevue's climate is marine-influenced. Expect rain from October through April. Trails remain open year-round, but muddy conditions on soft-surface paths are common in winter. Waterproof footwear is advisable in the off-season.
What to bring:
- Water and snacks (no food concessions in the park)
- Insect repellent in summer, particularly near standing water
- Binoculars if birdwatching
- Layers; temperatures can drop quickly near open water even on summer evenings
Emergency contact: In an emergency, call 911. For non-emergency park issues, contact the City of Bellevue Parks and Community Services department — verify the current contact number on the official City of Bellevue website (bellevuewa.gov).
Safety
Mercer Slough is a well-maintained urban park with no significant safety concerns for typical visitors. Trail surfaces near the boardwalks can be slippery when wet; use caution in rainy conditions.
The wetland habitat supports wildlife including coyotes, river otters, and the occasional black bear moving through the urban corridor — sightings are uncommon but possible. Follow standard wildlife awareness practices: do not feed animals, keep dogs leashed, and give any wildlife ample space.
The park is popular and generally well-trafficked during daylight hours, which contributes to a safe visitor environment. Stick to marked trails; venturing off-trail into marshy areas risks getting stuck in soft ground and damages sensitive habitat.
Local Culture & Etiquette
The land within and around the Mercer Slough has a layered history. Indigenous peoples of the Puget Sound region, including ancestors of the Duwamish Tribe, used the waterways and wetlands of this area for fishing and travel for thousands of years before Euro-American settlement.
In the late 19th and early 20th centuries, the slough valley was drained and converted to farmland, primarily for growing vegetables and, notably, blueberries. The Winters House dates to this agricultural era and is listed on historical registers. The survival of Shamrock Farm as a working blueberry operation within the park is a deliberate preservation choice by the City of Bellevue, maintaining a tangible connection to that farming heritage.
Conservation of the slough began in earnest in the 1970s and 1980s as Bellevue grew rapidly. The park represents a deliberate civic decision to protect wetland function and biodiversity inside an urban boundary — a history that informs how Bellevue presents itself as a city that integrates nature into its urban fabric.
