Update: In 2020 the American Ornithological Society merged Northwestern Crow into American Crow. All crows in the Fraser Valley are now American Crows. The account below was written before the merge.
Range as currently understood is restricted to the eastern part of the checklist area from Hope eastwards. Northwestern Crow is coastal and found west of Hope. Undoubtedly this species is able to wander and since American Crows seem more at home in remote locations, some casual suggestions of crows spotted in remote, mountainous areas west of Hope could be American Crows. It will be tough to confirm that theory.
Similar species:
Slightly larger than Northwestern Crow and with a higher pitched voice. However, western populations of American Crow are smaller with hoarser voices. Currently the only reliable method to separate the species is by their range. Common Raven is larger with a heavier bill and wedge shaped tail.
Sources:
Ehrlich, Dobkin and Wheye, (1988)
Photos
