JACKSON, Wyo. — The Greater Yellowstone Ecosystem is the only place in the United States where bison have lived continuously since prehistoric times; arguably no other animal symbolizes the West as does the American bison.

The bison herd seen today in Grand Teton National Park began as a herd of 15 bison that escaped a fenced wildlife park near Oxbow Bend in 1968. The Park Service allowed the herd to roam free and it now numbers over 500 animals.

Today, during the winter months, areas around the Snake River, Buffalo Fork River and Kelly Warm Springs are closed to all travel from Dec. 15 through March 31 to protect ungulate populations including, moose, elk, mule deer, bison and pronghorn.