On his bicycle ride from Pierre, South Dakota to North Pole, Alaska author Gary Wietgrefe encountered hundreds of wood bison along his route through British Columbia and the Yukon Territory. He writes extensively about them in his book, Destination North Pole—5,000 km by bicycle. Wood bison, the largest North American land mammal, is wild, extremely dangerous, tend to graze along open paths (like highway ditches) and are 20% larger than Plains bison. Both types of bison (often referred to as “Buffalo”) are distinct subspecies saved from extinction in the late 1800s and have since repopulated the U.S. Plains and boreal forests south of the Arctic Circle. South Dakota’s Buffalo Roundup (1,300 animals) is an annual event to check the herd and cull to maintain a healthy population in the massive Custer State Park in southwest South Dakota.