Fewer than 1,000 animals live in the lower 48 U.S. states, mainly around Yellowstone and Glacier national parks. Outside Alaska, the U.S. brown bear population is listed as threatened. Scattered small populations in other areas, such as in Europe, are endangered, with sometimes only a few individuals remaining. Brown bears live in a wide variety of open, or semi-open, northern habitats, including grasslands, coastlines, tundra, and mountain and lowland forests. Seasonally, salmon or trout are important foods.
Females reach maturity between four and ten years old, and average about two cubs every four years.
Male and female brown bears mate in late spring or early summer. Young, usually two or three cubs, are born in the mother's winter den between January and March. Usually, brown bears stay in their dens until April, May, or June. Young stay with the mother for one and a half to four and a half years. Brown bears live up to 30 years in the wild, and close to 50 years in zoos.