Seismic faults in Washington State
The principal Puget Sound faults (approximate location of known extents) and other selected peripheral and minor faults. Southern tip of Vancouver Island and San Juan Islands at top left (faults not shown), Olympic Mountains at center left, Mount Rainier at lower right (near WRZ). Faults north to south: Devils Mountain , Utsalady Point , Strawberry Point , Mount Vernon Fault/Granite Falls FZ/Woods Creek , Monroe Fault , Little River , Sequim , Southern Whidbey Island Fault , Cherry Creek , Tokul Creek , Rattlesnake Mountain Fault Zone , Lofall , Canyon River , Frigid Creek , Saddle Mountain faults , Hood Canal , Dabob Bay , Seattle Fault Zone , Dewatto Lineament , Tacoma Fault Zone , East Passage , White River (extends east), Olympia Structure , Scammon Creek , Doty (extends west), Western Rainier Zone , Saint Helens Zone (extends south). Also shown: Victoria (V), part of the Leech River Fault (unlabeled), and part of the Olympic–Wallowa Lineament .
The Puget Sound faults under the heavily populated Puget Sound region (Puget Lowland) of Washington state form a regional complex of interrelated seismogenic (earthquake-causing) geologic faults. These include (from north to south, see map) the: