Bull Trout is a member of the trout and salmon family. It has a long and slender body, a large broad head with a prominent upper jaw, and a slightly forked tail fin. Its back is olive-green to blue-grey and its sides are silvery with small pink, lilac, yellow-orange or red spots. Its belly is pale coloured and may become yellow, orange or red in males during spawning. Pelvic and anal fins have white leading edges with no black line.
Length varies based upon its life history (see habitat and biology):
Resident, 250 to 410 mm.
Fluvial, 400 to 730 mm.
Adfluvial, 400 to 900 mm.