Alberta's economy is based on mining, fishing, manufacturing, farming and forestry. Fifteen percent of the annual gross domestic product comes from mining. Coal, natural gas and crude oil are the primary products. Coal is found in the foothills of the Rocky Mountains. Commercial fishing brings in 2,200 metric ton a year. Manufacturing accounts for 9% of the annual gross domestic product. Processed foods, refined petroleum, machinery, fabricated metals, paper products and wood products are manufactured. A small income comes from farming and forestry-about 4%. Farmers produce livestock and livestock products. Trees are used for local lumber. Forests cover 39% of the province.