Montana bears include two of the three species found in North America, the brown bear (including grizzly) and black bear.
The two parks where you are most apt to encounter Montana bears are Yellowstone National Park and Glacier National Park. The grizzly is a subspecies of brown bear. It is anywhere from 200 to 300 pounds heavier that a black bear and is generally more aggressive. The color (brown or black) is not necessarily an indicator of which species the bear is. A brown bear can be blackish in color and vice versa. In addition to size, you can differentiate a grizzly by the hump at the nape of their neck that gives them a bull-like appearance and a dish-shaped silhouette. Like all eight species of bears worldwide, Montana bears are generally solitary. You will rarely see them in groups other than courting couples and mothers with cubs.
While human-bear conflict is rare, anyone who ventures out in Montana's wilderness should be bear aware. A hiker was killed in Yellowstone National Park by a bear in July of 2011 when he and his companion happened on the animal. While this is a tragedy, it was the first bear-caused fatality in the park since 1986. Bear safety tips for hikers and campers include traveling in groups of at least three people and making noise when approaching a blind spot in a trail; bears will generally move away if they hear people approaching. Carry food in sealed containers and suspend it from a tree for storage. Don't wear scent and carry pepper spray, which is available in outdoor stores around the state. Do not feed bears and do not approach them. If you encounter a bear in the wild, make yourself bigger by joining hands with your companions and backing away slowly without making eye contact.