The Tualatin River COA (95 mi2) extends along the lower Tualatin River from just below Hagg Lake down to the confluence with the Willamette River. The area includes the associated floodplains, numerous tributaries, and associated upland habitats. This COA is adjacent to the Scoggins Valley – Mount Richmond and Gales Creek COAs.
Ecoregions
Key Habitats
Grasslands
Grasslands include a variety of upland grass-dominated habitats, such as upland prairies, coastal bluffs, and montane grasslands.
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
California Floater Mussel (Observed)
Anodonta californiensis
California Myotis (Observed)
Myotis californicus
Chipping Sparrow (Observed)
Spizella passerina
Clouded Salamander (Modeled Habitat)
Aneides ferreus
Coastal Cutthroat Trout (Documented)
Oncorhynchus clarki clarki
Columbia Torrent Salamander (Modeled Habitat)
Rhyacotriton kezeri
Common Nighthawk (Observed)
Chordeiles minor
Fringed Myotis (Modeled Habitat)
Myotis thysanodes
Hoary Bat (Modeled Habitat)
Lasiurus cinereus
Lewis’s Woodpecker (Observed)
Melanerpes lewis
Northern Red-legged Frog (Observed)
Rana aurora
Nelson’s checkermallow (Observed)
Sidalcea nelsoniana
Northern Spotted Owl (Observed)
Strix occidentalis caurina
Olive-sided Flycatcher (Observed)
Contopus cooperi
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
Townsend’s Big-eared Bat (Observed)
Corynorhinus townsendii
Western Bluebird (Observed)
Sialia mexicana occidentalis
Western Gray Squirrel (Observed)
Sciurus griseus
Western Meadowlark (Observed)
Sturnella neglecta
Western Painted Turtle (Observed)
Chrysemys picta belli
Northwestern Pond Turtle (Observed)
Actinemys marmorata
Western Ridged Mussel (Observed)
Gonidea angulata
White rock larkspur (Observed)
Delphinium leucophaeum
Willow Flycatcher (Observed)
Empidonax traillii
Winged Floater Mussel (Observed)
Anodonta nuttalliana
Yellow-breasted Chat (Observed)
Icteria virens auricollis