Species: Anodonta wahlametensis

D - 1000-5000 square km (about 400-2000 square miles) - D - Historic distribution includes the Lower Willamette River, and lower Columbia River in Oregon and Washington, and in northern California down to the San Joaquin Valley (Frest and Johannes, 1995; Taylor, 1981; Henderson, 1929). Frest and Johannes (1995) cite original distribution as the Lower Willamette River, and lower Columbia River in Oregon and Washington from The Dalles to the mouth; and in larger slow streams of northern California as far south as the northern San Joaquin Valley (including Wahkiikum, Cowlii, Clark, Skamania, and Klickitat Cos., Washington; Clatsop, Columbia, Multnomah, Clackamas, Marion, Hood River, and Wasco Cos., Oregon; and Siskiiou, Shasta, Lassen, Modoc, Tehama, Glenn, Butte, Yuba, Sutter, Yolo, and Sacramento watersheds., California). Currently, it is thought to be restricted to the Fall River in California and one possible specimen was reported from The Dalles (Wasco Co., Oregon) in 1990 (Frest and Johannes, 1995). Frest and Johannes (1995) notes it could also be surviving in other areas with deep pools and oxygenated substrates. Mock et al. (2004) further differentiated Glenn and Solano Co., California, specimens as <i>Anodonta wahlamatensis</i> thereby limiting <i>Anodonta californiensis</i> populations to Utah and Arizona (Black River in Apache).