structure and origin, the Olympic–Wallowa Lineament (OWL). This is a seemingly accidental alignment of topographic features that runs roughly east-southeast from the north side of the Olympic Peninsula to the Wallowa Mountains in northeastern Oregon. It aligns with the West Coast fault and Queen Charlotte Fault system of strike-slip fault zones (similar to the San Andreas Fault in California) on the west side of Vancouver Island, but does not itself show any significant or through-going strike-slip movement. It is of interest here because the various strands of the Seattle Fault change orientation where they appear to cross the OWL, and various other features, such as the Rosedale monocline and Olympia structure, and a great many local topographical features, have parallel alignments. It may also be the original location of the Darrington—Devils Mountain Fault (the dashed line "X" at the top of the following map). The OWL appears to be a deep-seated structure over which the shallower crust of the Puget Lowland is being pushed, but this remains speculative. Uplift and basin pattern Most of these "faults" are actually zones of complex faulting at the boundaries between sedimentary basins (synclines, "∩") and crustal uplifts (anticlines, "∪"). There is a general pattern where most of these faults partition a series of basins and uplifts, each about 20 km wide. From the north these are (see the map at right): Devils Mountain Fault zone (including Strawberry Point and Utsalady Point faults) ∪ Everett Basin Southern Whidbey Island Fault (SWIF) ∩ "Uplift of unknown origin" (Port Ludlow) Kingston arch (Lofall Fault) ∪ Seattle Basin Seattle Fault zone (approx. lines E-F) ∩ Seattle Uplift Tacoma Fault Zone (approx. line C) ∪ Tacoma Basin Olympia fault (approx. line A) ∩ Black Hills Uplift Doty Fault / Scammon Creek Fault (dashed lines) ∪ Chehalis Basin The Hood Canal Fault (and its possible extensions) and Saddle Mountain faults to the west are believed to form the western boundary to all this. On the east, the Devils Mountain Fault connects with the south striking Darrington Fault (not shown) which runs to the OWL, and the Southern Whidbey Island Fault extends via the Rattlesnake Mountain Fault Zone (dashed line) to the OWL. South of the OWL a definite eastern boundary has not been found, with some indications it is indefinite. (E.g., the Olympia Fault is aligned with and appears to be the northernmost member of a set of faults between