How do you keep someone from stealing your belongings? one answer is to lock them up. Another answer is to put a mark on them. Then others will know that they are yours. Both ways have worked for years. On the great grasslands of North America, ranchers raise cattle. The land of the Great Plains stretches from Mexico and Texas in the south to Saskatchewan in the north. Some of the land is too dry to raise crops. However, the thick natural grass of the plains is good food for animals. Much of the land belongs to national governments. Ranchers pay their governments for"grazing rights." In other words, they pay for each cow that grazes on the national land. The cattle roam on the"free range" and eat all the grass they want. The grasslands are free of fences, not free of cost.