The echinoids Salenia cascadensis n. sp., Stomechinus? dissimilaris n. sp., Glyptocidaris sp., Arbacia abiquaensis n. sp., Lytechinus baldwini n. sp., Gagaria crenularis n. sp., and Kewia marquamensis n. sp. occur in the Late Oligocene (Chattian) Scotts Mills Formation near Silverton, Oregon, just north of 45°N latitude. The echinoids occur in shallow-water sediments deposited among basaltic sea stacks along a rockbound, storm-dominated marginal marine environment. Except for Kewia, these occurrences mark a more northerly limit for these genera in the northeastern Pacific and add to their stratigraphic range.