In summer, bison roamed freely, 夏季 美洲野牛四处漫步
Male bison weigh in at one ton. 公野牛重达一吨
And a century ago, the bison were reduced to barely 1,000. 一百年前 野牛的数量曾锐减至不到一千
There were once 60 million bison, 这里曾有六千万只北美野牛