The european bison is an almost iconic animal rescued in the last minute of the Twentieth Century at the very point of extinction. Nowadays, this magnificent animal continues its fight for survival in places as San Cebrián de Muda. The bison has been traveling companion of the human being as long as our history goes. It has helped modeling the landscape as we see it today. Humans have been hunting these animals for over ten thousand years ago, to our days. To our ancestors, these animals were a mythical symbol-laden animal. They made great amount of resources from the bison. They admired the animal; They admired the animal; so attests the large amount of cave paintings and engravings found along the history. The european Bison is the biggest wild herbivore mammal in Europe. It is a powerful figure with agile movements showing strength and a majesty of the primitive nature. The european bison faces its own Sword of Damocles regarding its future. Each and every specimen is descendant of twelve primary bisons. These twelve belong to two different lines of breeding that cannot be mixed in order to avoid genetic viability. This situation is hopeless for the time being and keeps the animal continuously threatened, since successive generations of children of the same parents may develop genetic problems affecting the lives of the future bisons.