When temperatures plunge, the American bison couldn't care less. These burly mammals are ready for snow with their shaggy coats and massive bodies weighing up to 2,000 pounds. Our homepage bison are pictured in Yellowstone National Park in Wyoming, home to one of the largest and oldest herds in the country. Bison have roamed here since prehistoric times.

Wildlife conservationists, Native American tribes, and ranchers have campaigned to establish National Bison Day as a federally recognized holiday on the first Saturday in November. In 2016, President Barack Obama signed the law establishing the American bison as the national mammal of the United States. The US has come a long way in the protecting this grand animal, which was on the verge of extinction just over a century ago. The establishment of the American Bison Society in 1905, of which President Theodore Roosevelt was a founder, helped spearhead conservation efforts and bring these giants back from the brink.