Bushes and grass grow in most of the Kalahari, but the southwest has sand dunes and little plant life. The Okavango River rises in Angola and flows into northwestern Botswana. There, the river divides into streams and forms the Okavango Swamps, a vast marshland. Botswana has a dry, subtropical climate. Winter days are warm, but the temperature often falls below freezing at night.
Droughts occur frequently.
Botswana is a poor country, but its economy is developing rapidly. The nation's two chief industries are mining and the raising of livestock, especially cattle. Copper, diamond, and nickel deposits were discovered in Botswana in the late 1960's and the 1970's and are being developed today. Botswana also has deposits of coal and cobalt. Farmers raise corn, millet, sorghum, and other crops.