After the Civil War, many Americans turned towards settling the western frontier: "the Great American Desert". While the winter blizzards and hot dry summers stop people from wanting to settle, the open grasslands of the plains support an estimate of 15 million bison. They provide food, clothing, shelter, and even tools for many of the 250,000 Native Americans living in the west since 1865. In only 35 years, conditions on the Great Plains changed to the point that there was virtually no more frontier. The great buffalo herds have been wiped out. The open western lands were not fenced in by homesteads and ranches, crisscrossed by steel rails, and modernized by new towns. Ten new western states have been created, leaving only Arizona, New Mexico & Oklahoma as territories awaiting statehood. Progress came with a cost, the rush for West's natural resources cause near the extermination of buffalo & damage to the environment. The Native Americans who happen to be in the way of development also seem to pay a high human and cultural price. The settlement of the last frontier is achieved by three groups of pioneers: miners, cattlemen & cowboys, and farmers.