Tahkenitch-Siltcoos Lakes – State Wildlife Action Plan

Tahkenitch and Siltcoos Lakes Area — Photo Credit: Doug Cottam, ODFW

The Tahkenitch-Siltcoos Lakes COA (118 mi²) extends from Honeyman State Park east toward Mount Peter and down the coastline to Threemile Lake. Two large coastal lakes with floating peat islands and a large numbers of wintering waterfowl exist in this COA. This COA is adjacent to the Siuslaw River Estuary, North Fork Smith River, and Umpqua River Estuary COAs.

Recommended Conservation Actions

Limit the placement of docks and boathouses in the lakes, follow ODFW dock guidelines or use established public ramps.
Place large woody debris in stream channels to increase habitat complexity for fish and wildlife.
Protect and restore shorelines from hardening and dynamic revetment modifications (rip rap, rock, etc).
Protect shoreline habitat for rare plants.
Remove remaining dikes to recover lost wetland and floodplain habitats.

Local Conservation Actions and Plans

Special Features

General

Extensive peat bog/fen wetlands (some are floating).
Numerous Bald Eagle and Osprey nesting sites.
Snowy Plovers successfully nest along the shoreline.
Carnivorous pitcher plants (Darlingtonia) are found along the edges of the lakes.

Protected Areas

Ada County Park
Jessie M. Honeyman Memorial State Park
Oregon Dunes
Siuslaw National Forest
Tahkenitch Dune
Westlake Park

Previously Associated With

Previously Associated with (2006 COAs)
- CR-27 (Siltcoos – Tahkenitch Basin)

- CR-28 (North Fork Smith River)

Size Change from 2016 boundaries: +3.2 mi² (3% increase)

Specialized Local Habitats

Aquatic vegetation beds
Forest openings
Interdunal lakes and wetlands
Off channel habitats
Peatland fens

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 …