In southern portions, such as Washington, Oregon and northern California, black bears are the only bears to be found. Black bears come in many colors, including brown, and may be mistaken for a brown bear where their ranges overlap. There are some differences that help make identifying the type of bear rather easy. Black bear claws are more curved and better suited for climbing. A black bear, when viewed from behind, has a droopier looking backside than a brown bear does.
Black bears are, on average, smaller than brown bears.
A small adult brown bear would weigh about the same.