The results of this study indicate the historic range of Cicindela hirticollis abrupta Casey was limited to only five sites within the Sacramento Valley of California. Extensive searches within and beyond its historic range along the Feather and Sacramento Rivers in 2001–2004 failed to find any individuals of this tiger beetle and very little suitable habitat. Another tiger beetle, C. o. oregona Dejean, which occurs in a much greater array of water edge habitats, was common at some sites. The cumulative effects from the Oroville and Shasta Dams, including loss and deterioration of sandy edge river habitats and prolonged high water levels, probably caused the extirpation of C. h. abrupta in the late 1980's to early 1990's.