Although overall the Great Plains are sparsely populated, with much of the grassland devoted to farms and ranches, about half the people live in small to medium-sized urban areas; Edmonton, Alberta and Denver, Colo. are the largest cities in the region. Soils throughout the region are fertile and very productive when water is available. The principal crop is wheat, concentrated in the Spring Wheat Belt (generally N of Nebraska), where the colder climate delays sowing until spring, and the Winter Wheat Belt (centered in Kansas and Oklahoma), where the milder climate allows for winter sowing. Other crops include sorghum, flax, and cotton. Cattle and sheep are raised throughout most of the Great Plains. Oil, natural gas, coal, and gold are among its mineral deposits.