The Santiam Confluences COA (109 mi2) extends from the confluence of the mainstem with the Willamette River upstream along the North Fork Santiam through confluences with Jefferson Ditch and Valentine Creek, up toward Mill Creek. This COA also extends along the South Santiam River through confluences with Spring Branch, Thomas Creek, Spring Creek, Crabtree Creek, Onehorse Slough, and Noble Creek toward Sweet Home. This COA is adjacent to the Little North Santiam River Area, Kingston Prairie – Scio Oak Pine Savanna, Salem Hills – Ankeny NWR, Middle Willamette River Floodplain, and One Horse Slough – Beaver Creek COAs.
Ecoregions
West Cascades
The West Cascades ecoregion extends from east of the Cascade Mountains summit to the foothills of the Willamette, Umpqua, and Rogue Valleys, and spans the entire length of the state of Oregon. It is largely dominated by conifer forests, moving into alpine parklands and dwarf shrubs at higher elevations.
Willamette Valley
The Willamette Valley ecoregion is bounded on the west by the Coast Range and on the east by the Cascade Range. This long mostly level alluvial plain has some scattered areas of low basalt, and contrasts with productive farmland and large urban areas. It has the fastest-growing human population in the state resulting in challenges due to land-use changes.
Key Habitats
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 …
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.
Species of Greatest Conservation Need
Acorn Woodpecker (Observed)
Melanerpes formicivorus
Bradshaw’s desert parsley (Observed)
Lomatium bradshawii
California Myotis (Modeled Habitat)
Myotis californicus
Cascade Torrent Salamander (Modeled Habitat)
Rhyacotriton cascadae
Chipping Sparrow (Observed)
Spizella passerina
Clouded Salamander (Modeled Habitat)
Aneides ferreus
Coastal Cutthroat Trout (Documented)
Oncorhynchus clarki clarki
Common Nighthawk (Observed)
Chordeiles minor
Foothill Yellow-legged Frog (Observed)
Rana boylii
Fringed Myotis (Modeled Habitat)
Myotis thysanodes
Western Grasshopper Sparrow (Observed)
Ammodramus savannarum perpallidus
Hoary Bat (Modeled Habitat)
Lasiurus cinereus
Northern Red-legged Frog (Observed)
Rana aurora
Northern Spotted Owl (Modeled Habitat)
Strix occidentalis caurina
Olive-sided Flycatcher (Observed)
Contopus cooperi
Oregon Chub (Documented)
Oregonichthys crameri
Oregon Slender Salamander (Modeled Habitat)
Batrachoseps wrighti
Oregon Vesper Sparrow (Observed)
Pooecetes gramineus affinis
Western Purple Martin (Observed)
Progne subis arboricola
Short-eared Owl (Observed)
Asio flammeus flammeus
Silver-haired Bat (Modeled Habitat)
Lasionycteris noctivagans
Southern Torrent Salamander (Modeled Habitat)
Rhyacotriton variegatus
Townsend’s Big-eared Bat (Modeled Habitat)
Corynorhinus townsendii
Western Bluebird (Observed)
Sialia mexicana occidentalis
Western Gray Squirrel (Modeled Habitat)
Sciurus griseus
Western Meadowlark (Observed)
Sturnella neglecta
Western Painted Turtle (Observed)
Chrysemys picta belli
Northwestern Pond Turtle (Observed)
Actinemys marmorata
Western Rattlesnake (Modeled Habitat)
Crotalus oreganus oreganus
White-topped aster (Observed)
Sericocarpus rigidus
Willamette daisy (Observed)
Erigeron decumbens
Willow Flycatcher (Observed)
Empidonax traillii
Yellow-breasted Chat (Observed)
Icteria virens auricollis