Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Onlookers watch riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Riders drive bison at the annual Antelope Island Bison Roundup, Friday October 25, 2013.Trent Nelson | The Salt Lake Tribune Horses nuzzle before the annual Antelope Island Bison Roundup, Friday October 25, 2013.