Before this study, the mosquito Ochlerotatus (Finlaya) togoi (Theobald) had been reported fromonly 2 locations within the continental Unitid States, both of which were documented in Washington State. Thisstudy used active and passive surveillance to determine the current distribution of Oc. togoi along the PacificCoast of Washington. Results of the study show that small, but stable, populations of Oc. togoi exist in thenorthern San Juan Island region of Puget Sound. Geological formations in this region are conducive to rockholes and support populations of Oc. togoi. No members of Oc. togoi were found on the southwestern Washingtoncoast, the coast of the Olympic Peninsula, or in the lower Puget Sound.