Every autumn, riders thunder across the grassland to gather the park's herd of 1,300 bison. The state's calendar fills each year with events that draw crowds from far beyond its borders.

Cowboys and cowgirls on horseback drive the herd into corrals each fall.

What sets it apart

Tens of thousands of spectators gather to watch the roundup. That detail is easy to overlook, but it helps explain the pull this place has on locals and visitors alike.

The event doubles as a health check and herd-management tool.

Why it matters

What ties it all together is a distinctly South Dakota balance between the wild and the worked-over. For the crowds who return year after year, it has become a fixture of the South Dakota calendar.