Columbia River-Blind Slough Swamp – State Wildlife Action Plan

The Columbia River near the Blind Slough in Oregon's Coast Range Ecoregion. Photo Credit: Herman Biederbeck, ODFW

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 Columbia River – Blind Slough Swamp COA (144 mi²) is an large area on the lower Columbia River Estuary which extends from just east of Tongue Point upstream to Crims Island. The area includes many islands on the Oregon side of the Columbia River, as well as the Lewis and Clark National Wildlife Refuge and portions of the Julia B. Hanson Refuge for The Columbian White-tailed Deer. This COA also includes the Blind Slough Swamp Preserve, which has some of the only remaining Sitka spruce swamplands in Oregon. In addition, there are many important tributary streams flowing into the Columbia in this area, including Mary’s Creek, Gnat Creek and Big Creek. This area provides critical habitat for many fish and wildlife species including migratory and wintering waterfowl, coho salmon, Columbian white-tailed deer, and many more. This COA creates a contiguous chunk of habitat along with the Clatsop State Forest-Jewel Meadows Area and Clatskanie River COAs.

Recommended Conservation Actions

Maintain and restore floodplain wetlands, tidal wetlands and bottomland forests.
Improve fish passage and riparian vegetation in tributary streams.
Maintain and restore existing habitat and ecological function, ensuring sufficient habitat complexity for wildlife.
Manage public use and recreation to minimize disturbance to sensitive wildlife.

Local Conservation Actions and Plans

Potential Partners

Special Features

General

This area has some of the only populations of the federally threatened Columbian white-tailed deer (Odocoileus virginianus leucurus) in Oregon. This subspecies occurs in small numbers along the Columbia River, utilizing fragmented pockets of lowland and floodplain habitat. Due to the small and isolated nature of the population, this species is extremely vulnerable to population declines from disease, climate change, and continued habitat loss.
The islands along the Lower Columbia River provide critical habitat for a variety of bird species. These islands provide protected areas for breeding birds during the nesting season, from colonial species such as the Caspian Tern (Hydroprogne caspia) to the federally endangered Streaked horned lark (Eremophila alpestris strigata). The Streaked horned lark requires large expanses of open grassland for nesting – habitat which is created post-dredging on many of the Lower Columbia River Estuary islands.
Many waterfowl and shorebird species rely on the resources available within this COA during migration and while overwintering. The islands along the Lower Columbia River can host thousands of waterfowl during the fall and winter months, taking advantage of the optimal habitat and food resources available.
The Blind Swamp Slough (preserved by the North Coast Land Conservancy) contains some incredibly unique habitat, with Sitka spruce swamplands that are over 400-years-old. This is some of the highest quality remaining swampland of its kind in Oregon, and provides critical habitat for a huge variety of fish and wildlife species.
There has been an emphasis on chum salmon reintroduction/recovery in this area in recent years.
Land ownership along the Lower Columbia River is largely federal, while inland it is primarily Clatsop State Forest. There are smaller parcels of commercial timber and small private ownership dispersed throughout as well.

Protected Areas

Blind Slough Swamp Habitat Preserve
John Day River Marsh Habitat Preserve
Julia Butler Hansen Refuge for the Columbian White-Tailed Deer
Lewis and Clark National Wildlife Refuge
Wolf Bay Habitat Preserve

Previous COA Associations

Previously Associated with (2006 COA IDs)
- CR-02 (Columbia – Clatskanie area)
- CR-03 (Clatskanie River)
Size Change from 2016 boundaries: – 16.9 mi²(11% decrease)

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

Key Habitats

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 …

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, …