Jeff Henry: The Snowman, is a mini biography of sorts about Yellowstone National Park ranger Jeff Henry, whose obsession with (and jobs related to) snow helped the BBC crew identify the best places to capture the Park in the winter. This feature also explores how Henry does his job clearing snow from the Park.

In Geyser Gazers, the second of the three Extras, viewers learn how the BBC crew setup their picturesque geyser shots and the struggles they endured to capture all the amazing imagery in this miniseries. It also introduces viewers to the locals who acted as guides for the BBC crew and lent their first-hand knowledge of geyser schedules and "personalities."

Mike Kasic: The Fishman, viewers learn more about the man who helped BBC capture its fish scenes through his extensive knowledge of Yellowstone's waterways and fish.

在这六个寒冷的月里，随着冬季的到来，我们记录了黄石国家公园野生动物在一场为生存而进行的微妙而平衡的斗争中的命运。野牛和麋鹿在美国最深的积雪下挣扎着吃草，而狼在严酷的冬天变得更强壮。它们的命运最终都与黄石公园中心火山有关。

春天融化了冬天的积雪，黄石公园的全貌逐渐显露出来。现在，成群结队的麋鹿、叉角羚和野牛从它们的冬季觅食地回到这里，利用美国最富饶的天然草原。灰熊从冬眠中苏醒过来，教它们的幼崽捕食鱼类，以及如何在高山的山峰上生存。但就在夏季舒适的生活似乎已经到来之际，一种新的危险出现了。

初秋飘落的雪花标志着麋鹿开始从山上下来，专注于在下面的山谷里寻找食物。虽然狼在等着它们，公麋鹿却心烦意乱，它们很兴奋，准备为了繁殖的权利而互相争斗。海狸们忙着在池塘结冰之前修复水坝和储存水下食物。白皮松为灰熊和松鼠提供坚果，帮助它们增肥，因为所有的动物都在为下一个严冬做准备。