Siuslaw River Estuary – State Wildlife Action Plan

The Siuslaw River Estuary in Oregon's Coast Range ecoregion. Photo Credit: Oregon Coastal Management Program

Geographic boundaries of the COAs were updated for the 2026 State Wildlife Action Plan and the associated COA profiles are intended to provide additional information. Content of each COA profile is being refined and will be updated to reflect current conditions when feasible. Please help us by submitting information on Local Conservation Actions, Plans, or Potential Partners to: OCS.revision@odfw.oregon.gov.

The Siuslaw River Estuary COA (46 mi²) extends from the estuary in Florence up past Tierman. The estuary forms a small bay for the size of the Siuslaw River with many islands and salt/freshwater marshes. This COA is adjacent to the Sutton Lake Area, North Fork Siuslaw River, Siuslaw River, and Tahkenitch-Siltcoos Lakes COAs.

Recommended Conservation Actions

Limit the placement of docks and boathouses in the estuary.
Protect and restore estuarine shorelines from hardening and dynamic revetment modifications (rip rap, rock, etc).
Protect islands with threatened plant species.
Protect steep, landslide prone areas from harvest activities.
Protect the estuary from commercial shellfish development.
Remove remaining dikes and tide gated areas to recover lost salt marsh habitats.

Local Conservation Actions and Plans

Potential Partners

Bonneville Power Administration
Confederated Tribes of Coos, Lower Umpqua and Siuslaw Indians
Lane County
McKenzie River Trust
Oregon Department of State Lands
Oregon Parks and Recreation Department
Siuslaw Watershed Council
The Nature Conservancy
U.S. Bureau of Land Management
U.S. Forest Service
USDA Natural Resources Conservation Service
West Lane Soil and Water Conservation District

Special Features

General

Contains tidally influenced islands

Protected Areas

Harbor Vista County Park
Jessie M. Honeyman Memorial State Park
Joaquin Miller State Park
Prichard State Wayside Park
Siuslaw National Forest
Siuslaw North Jetty
South Jetty County Park

Previously Associated With

Previously Associated with (2006 COAs)
- CR-23 (Siuslaw River area)

- CR-25 (Sutton Lake area)
- CR-26 (Siuslaw River Estuary)
- CR-27 (Siltcoos – Tahkenitch Basin)

Size Change from 2016 boundaries: +5.0 mi² (12% increase)

Specialized Local Habitats

Bays
Eelgrass beds
Forest openings
Interdunal Lakes and wetlands
Intertidal mudflats
Sand spits, sandbars and sparsely vegetated islands

Ecoregions

Coast Range

Oregon's Coast Range, known for its dramatic scenery, is extremely diverse, with habitats ranging from open sandy dunes to lush forests and from tidepools to headwater streams. It follows the coastline and extends east through coastal forest to the border of the Willamette Valley and Klamath Mountains ecoregions

Nearshore

The Nearshore ecoregion includes a variety of habitats ranging from submerged high-relief rocky reefs to broad expanses of intertidal mudflats in estuaries and hosts a vast array of fish, invertebrates, marine mammals, birds, plants, and micro-organisms. This ecoregion encompasses the area from the outer boundary of Oregon's Territorial Sea to the supra-tidal zone, and up into the estuaries.

Key Habitats

Coastal Dunes

Occurring along the Oregon coastline, coastal dunes provide habitat for species that prefer open, sandy habitats with a high degree of disturbance from winds and tides.

Estuaries

Estuaries are broadly defined as partially enclosed coastal bodies of tidally influenced water with one or more inputs of freshwater, and with a free or intermittent connection to the open sea. Estuaries typically occur at locations where freshwater from rivers, streams, or creeks meets saltwater from the nearshore ocean, creating a tidal basin that experiences frequent …

Grasslands

Grasslands include a variety of upland grass-dominated habitats, such as upland prairies, coastal bluffs, and montane grasslands.

Late Successional Mixed Conifer Forests

Late successional mixed conifer forests provide a multi-layered tree canopy, including large-diameter trees, shade-tolerant tree species in the understory, and a high volume of dead wood, such as snags and logs.

Natural Lakes

Natural lakes are relatively large bodies of freshwater surrounded by land that were formed through geological processes, such as glacial scouring, tectonic movements, volcanic activity and river meander cutoffs. In Oregon, natural lakes are defined as standing water bodies larger than 20 acres, including some seasonal lakes. Depth is not a reference for characterization of …

Example of Oak Woodlands, which is a Strategy Habitat within the State Wildlife Action Plan

Oak Habitats

There are several oak habitat types in Oregon, where oaks comprise most of the canopy. These can include oak woodlands, oak forest, oak chaparral, and riparian oak. Oak savanna is covered in the Grasslands Key Habitat. Oaks may also co-dominate a canopy in oak/fir, oak pine, and oak hardwood habitats.

Flowing Water and Riparian Habitats

Flowing Water and Riparian Habitats include all naturally occurring flowing freshwater streams and rivers throughout Oregon as well as the adjacent riparian habitat.

Ducks on a wetland in Ladd Marsh Wildlife Area, Oregon

Wetlands

Wetlands are habitats that are inundated or saturated by surface water or ground water at a frequency and duration sufficient to support vegetation typically adapted for life in sodden soil conditions. While dominated by periods of inundation, the natural ecological cycle may also include dry intervals. Permanently wet habitats include backwater sloughs, oxbow lakes, peatlands, …

Nearshore Key Habitats

Nearshore Habitats encompass the coastal and marine habitats in the area from the 3 nautical mile outer limit of Oregon’s territorial sea, where water depths average 66 m (216 ft) and range from 17 m to 194 m (56 to 308 ft), to the supratidal areas of the shoreline affected by wave spray and overwash …