Excerpt: The grasslands, hay lands, and forested range lands of the entire United States cover more than a billion acres, nearly 60 percent of the total land area. They furnish about half of the feed for all livestock. Two-thirds of this land is privately owned. The rest, mainly in the dry and mountainous parts of the Western States, is publicly owned. More than half of the farms and ranches of the country depend largely on grassland for feed. Originally about 700 million acres in the United States were covered with grass, usually mixed with other herbaceous plants. Nearly 250 million acres of that grassland have been plowed up and used for crops or for pasture in rotation with crops, including about 10 million acres of irrigated land. The grasslands of the central prairies formed the largest body of highly productive soils in America; they have been converted almost entirely to cropland. Semiarid, desert vegetation characterized about 400 million acres, of which about 12 million acres have been reclaimed by irrigation.