Lake trout have a deeply forked tail and numerous white (light) markings on their body with no pink or orange spots on their sides. Brook trout have black markings on their back and dorsal fins along with red or orange spots on their sides surrounded by blue halos. Don't assume because a fish is small, it can't be a bull trout. Juvenile bull trout rear in small streams and can be confused with brook trout. If you don't know, LET IT GO.