Grizzlies can be large and imposing but their size is often overestimated. In summer, adult males weigh about 400-500 lbs and females about 250-350 lbs. In general adult grizzlies are almost twice the size of adult black bears. Typically they measure 3-4′ tall at the shoulder when on all four feet, and 6-8′ tall standing upright. Their fur is often brown, tipped with blonde for a "grizzled" or silvertip appearance, which is how they got their name.

Black bears are often present in grizzly bear country of northwest Montana. You can't always tell a grizzly from a black bear by color: some grizzlies are quite dark and some black bears are sunbleached and light. Grizzlies are distinguished by their dished face, prominent shoulder hump, and long claws. Grizzly claws are usually light colored and at least 2″ long.

Claws of adult grizzlies are rarely less than 1¾″ long. Claws of black bears seldom exceed 1½″.

Grizzly sign includes extensive digging, turned-over rocks, and ripped tree bark.