Millions of incredible animals roam, fly, swim and slither across our planet. Among the most iconic of these is the grizzly bear, a symbol of the American wilderness. Young grizzlies often "play-fight" to build strength, sharpen skills and establish social bonds. These heavyweight champs can weigh up to 410 kilograms and still sprint faster than most humans. Once widespread across the western United States, grizzlies now primarily roam Alaska and parts of the Northern Rockies.