Where Buffalo Thrived The prairie is originally covered in prairie grass, with a dense root system reaching down many feet (right). It comes back year after year, and can survive extended droughts. Cultivated wheat is also in the grass family, but has to be replanted each growing season. Its roots don't have time to penetrate very deeply, so irrigation is important to achieve consistent harvests in dry zones.

	Feeding the Livestock BLUE highlights indicate zones being irrigated, which have tripled in acreage in the previous 20 years. Western areas lacking irrigation remain virtually unsettled. The chart shows that almost all irrigated crops are grown as feed for livestock, showing how dependent even ranchers are upon irrigation. They need to be able to grow feed to keep cattle alive through the winter, when open grazing is severely limited.
	Anything and Everything The pictures across the top illustrate the range of farming activities in the prairie region, from small vegetable gardens to large field crops. The photo at bottom right is from the central California region, east of San Francisco. It shows the increasing scale of harvesting operations on western wheat fields. Few farmers can turn a consistent profit in this region, however, before large-scale irrigation projects are completed.