The geology of Oregon has become a jigsaw puzzle of moving parts set on a foundation of changing conditions as the crust and mantle undergo successively different manners of deformation through time. As more megahypotheses arise from increasingly sophisticated views of plate tectonics and from more detailed analyses of synoptic images from outer space, it is the task of the geologist to continue to provide sound and reliable ground truth with which to test them. For now it would appear that large overviews from such investigations may include: 1) Possible large-scale bending and dislocation of pre-Mesozoic structures in the subsurface to give an arc-like distribution. 2) Large-scale regional and multiple thrust faulting in the Klamaths through much of the Mesozoic Era. 3) Explosive volcanism in the mid-Tertiary possibly representing subduction. 4) Tensional tectonics represented by Columbia River Basalt eruptions in the mid-Miocene and later block faulting in the Basin and Range province of southeastern Oregon. The Brothers fault zone and its possible extensions may represent the northern boundary of block faulting of the Basin and Range. 5) Possible division of the State into four blocks separated by northwest trending shear zones. A system of north-south compression could account for northeast-trending linears as well. 6) Possible tensional block faulting and graben structures beneath the flows of the Cascades Formation (High Cascades).