Eel River Estuary Preserve

Eel River Estuary Preserve and the adjoining Sounding Seas Dunes Reserve are nature preserves in California that protect the estuary at the mouth of the Eel River, together with surrounding wetlands, dunes, and shoreline habitats.^[1] The landscape includes tidal marshes, a half-moon bay, and small islets that serve as haul-out sites for seals.^[1] They are part of the Eel River Emerald Necklace, a series of preserves along the Eel River.^[2][3] Together the preserves total 1,300 acres (530 ha) and are owned and managed by The Wildlands Conservancy as part of its system of preserves.^[1]

The preserves protect tidal wetlands, freshwater marsh, grasslands, beach, and dunes at the southern end of the Eel River estuary.^[1] The landscape includes a half-moon bay, coastal habitats used by migratory waterfowl, and a small island that serves as a haul-out site for seals. There is a transition from the estuary to dunes and then to the Pacific Ocean.

The Eel River estuary supports tidal marshes, freshwater wetlands, grasslands, dunes, intertidal flats, and eelgrass beds. Independent surveys document the estuary as critical rearing habitat for juvenile salmonids such as Chinook and coho salmon and steelhead trout, with high densities of juvenile Chinook using the estuary in summer months to increase in size.^[4][5] The estuary also provides seasonal habitat for migratory birds and has been identified as a focal point for salmon recovery in the watershed.^[6] The dunes provide habitat for the federally endangered snowy plover and the rare beach layia.^[7]

The estuary lies within the Eel River Delta and Humboldt Bay complex, designated as an Important Bird Area by the National Audubon Society for its importance to resident and migratory bird populations.^[8] The Pacific Birds Habitat Joint Venture identifies the delta as one of the largest coastal wetlands between San Francisco Bay and the Columbia River, supporting hundreds of thousands of shorebirds and waterfowl annually, and recognizes the mouth of the Eel River as part of a site of International Importance under the Western Hemisphere Shorebird Reserve Network.^[9] Notable species reported in the area include Aleutian cackling geese, brant geese, bald eagles, snowy plovers, long-billed curlews, egrets, herons, and tundra swans, the latter of which winter regularly in the estuary as part of the Pacific Flyway population.^[1][10]

Marine mammals are present in the estuary, with harbor seals using established haul-out sites near the river mouth, and sea lions, dolphins, and porpoises occasionally entering during seasonal fish runs.^[11]

In 1974, the California Department of Fish and Wildlife identified the southern estuary as a top conservation priority for the Eel River. The Wildlands Conservancy purchased the former Connick Ranch in 2008, creating the Eel River Estuary Preserve.^[12] The following year, the conservancy acquired the adjoining dunes, establishing the Sounding Seas Dunes Reserve.^[1] These acquisitions were part of The Wildlands Conservancy’s Eel River Emerald Necklace project to establish a system of preserves along the Eel River.^[13]

The preserve lies at the downstream end of the Eel River Emerald Necklace, which The Wildlands Conservancy describes as a landscape-scale conservation initiative forming a network of preserves along the Eel River corridor.^[2] Regional studies by California Sea Grant identified the estuary lowlands as an important area for tidal wetland restoration and climate resilience.^[14] Early proposals from California Trout highlighted the potential to restore tidal inundation by removing dikes and reconfiguring channels.^[15][16] Support for restoration was later expressed in public letters to the California Ocean Protection Council.^[17] The Wildlands Conservancy participated in regional “Climate Ready” studies, hosting transects and a demonstration site on the preserve to assess dune erosion and foredune restoration techniques.^[18]

In August 2025, the California Coastal Commission approved the Russ Creek and Centerville Slough Restoration Project, which covers about 1,500 acres (610 ha) of estuary lands, including much of the preserve.^[19] The project involves conservation easements with multiple landowners, including The Wildlands Conservancy, and was characterized as one of the largest coastal restoration efforts on private land.^[19] Planned work includes tidal gate repair, removal of levees and berms, barn demolition, and construction of a new setback berm.^[19] Supporters cited benefits for salmon and climate resilience, while representatives of the Wiyot Tribe opposed the project, citing cultural impacts, insufficient consultation, and concerns about continued grazing on the property.^[19] Environmental groups, including Friends of the Eel River and the Surfrider Foundation expressed conditional support, urging greater attention to Indigenous perspectives.^[19] The project is expected to cost about $20 million and is scheduled for construction from 2026 to 2028.^[20]

Public access to the preserve has been limited,^[1] but the approved restoration plan includes expanded public access. The approved project includes a five-mile public access easement along the beach between Centerville Beach County Park and the mouth of the Eel River, new kayak launch stations, and about three miles of trails.^[19] The plan provides for year-round access for passive recreation and outdoor education.^[20]

• List of The Wildlands Conservancy preserves
• Seawood Cape Preserve

• Eel River Estuary Preserve – official site
• Sounding Seas Dunes Reserve – official site
• Eel River Emerald Necklace – The Wildlands Conservancy