Cranial mountain exposed the great massacre of bison

The massacre of the natives and migrants has caused the number of bison to drop from 60 million to less than 1,000.

In April 2016, the US Congress passed a law that ranked the largest bison , the largest animal on the mainland, into the national list. This drafted two-party law awaits President Obama's approval or veto decision, according to Business Insider.

The bison skull mountain in the photo taken in 1870 is waiting to be crushed and mixed into fertilizer.(Photo: Wikimedia Commons).

Bison has been wandering on plains of up to 60 million, meeting the demand for food, clothing, shelter and fuel for indigenous people to maintain their lives. Many tribes in America still consider bison as a sacred spiritual symbol for their history.

However, the process of expanding westward during the nineteenth century almost eliminated the bison from the North American plains. Settlers killed 50 million cows for food and entertainment hunting. Bison standing on the brink disappeared completely, according to the US National Park Authority.

The bison may become a US national.(Photo: Flickr).

In 1800, the number of bison was estimated at 40 million. In 1883, there were only a few wild bison living in the United States and mostly concentrated in Yellowstone National Park. In 1900, North America had fewer than 1,000 cows.

The massacre loses the most important resource of Native Americans. Thanks to the collective efforts of breeders, conservationists, tribes and authorities, bison was revived from the brink of extinction with the current number of about 500,000.