Olympic-Wallowa Lineament - Location

Location

Raisz located the OWL particularly from Cape Flattery (the northwest corner of the Olympic Peninsula) and along the north shore of Lake Crescent, thence the Little River (south of Port Angeles), Liberty Bay (Poulsbo), Elliot Bay (setting the orientation of the streets in downtown Seattle), the north shore of Mercer Island, the Cedar River (Chester Morse Reservoir), Stampede Pass (Cascade crest), the south side of the Kittitas Valley (I-90), Manastash Ridge, the Wallula Gap (on the Columbia River where it approaches the Oregon state line), and then the South Fork of the Walla Walla River into the northeastern corner of Oregon. After crossing the Blue Mountains Riasz associated the OWL with a dramatic scarp on the north side of the Wallowa Mountains. Riasz observed that the OWL tends to have basins on the north side (Seattle Basin, Kittitas Valley, Pasco Basin, Walla Walla Basin) and mountains on the southern side (the Olympics, Manastash and Umtanum ridges, Rattlesnake Mountain, the Horseheaven Hills, the Wallowa Mountains), and noted parallel alignments at various points, generally about four miles north or south of the main line. The alignment of these particular features is somewhat irregular; modern maps with much more detail show a broad zone of more regular alignments. Subsequent geological investigations have suggested various refinements and adjustments.