Bison are large animals with big heavy brown fur. Also called buffalo, they are the largest mammals in North America. They stand about 1.83 meters at the shoulder and weigh up to just over 900 kilograms. In 2016, the American bison was officially named the national mammal of the U.S. Bison once numbered in the millions. Since prehistoric times, they moved around from the Appalachian to the Rocky Mountains in the United States. In the 19th century, people hunted them for meat and hides people used the skin and fur to make products. They were down to only a few hundred animals by the late 1880s, according to the U.S. Department of the Interior. Now their numbers are growing. There are an estimated 500,000 bison living in North America. They are increasing in part because they are helping restore lands in the U.S.