Even the mastodon is buried here, a long dead relative of modern elephants.
甚至连乳齿象都被埋在这里，
This was once a bear, but not like any bear in North America today.
这里曾经有熊，但是和如今的北美大陆的熊是有区别的。
Claw marks gouged into the cave wall showed the bear was not killed direct by the fall. It made a desperate attempt to climb back out.
山洞墙壁上挖凿的爪印显示出熊并非死于直接坠亡。它曾绝望地想爬出这个山洞。
It was a short-faced bear, an ice age heavyweight.
这是只短面熊，冰河时期的重量级人物。
What else can we tell about it from its bones? Its weight was more than 700 kilos, twice that of a grizzly bear today.
从这些骨头中我们还能了解到什么呢？它的重量超过700公斤，是今天灰熊的两倍。
Upright, it would've stood four meters tall. It was the largest flesh-eating mammal that ever walked the earth.
它直立的时候有四米高，也是有史以来最大的食肉哺乳动物。
The Wyoming cave, appropriately christened natural trap, provides a unique window of the Ice Age.
被命名为自然陷阱的怀俄明洞穴，为探究冰河世纪打开一扇门。
During its coldest era, much of North America was covered by huge ice sheets up to two miles thick, but as the continent began to warm, the ice sheets started shrinking.
在最寒冷的时期，北美的很多地方被厚达两英里的巨大冰块覆盖着，但是随着大陆逐渐变暖，冰盖开始减小。
Corridors began to open up along the coast and through the mountains, letting people migrate south from Alaska for the first time.
沿着海岸，穿过山脉，一条条通道显现出来，人们第一次从阿拉斯加向南迁移。
Before them lay the almost limitless great plains stretching all the way from the Rocky Mountains to the Mississippi River and beyond to Mexico.
他们的面前是一望无际的大平原，一直从落基山脉延伸到密西西比河，越过了墨西哥。
Across this area, the shifting ice left deep scars on the land.
在这个区域，大块的浮冰运动在陆地上留下深深的印记。
They carved out thousands of lakes and ponds, and left the tapestry of streams and rivers that drained the plains.
它们刻画出成千上万的湖泊和池塘，勾勒出平原上如画般的溪流和小河。
