still an essential part of Wyoming's culture and lifestyle. The main agricultural commodities Wyoming produces include livestock (beef), hay, sugar beets, grain (wheat and barley), and wool. More than 91% of Wyoming's land is classified as rural. Wyoming is the home of only a handful of companies with a regional or national presence. Taco John's and Sierra Trading Post, both in Cheyenne, are privately held. Cloud Peak Energy in Gillette and U.S. Energy Corp. (NASDAQ: USEG) in Riverton are Wyoming's only publicly traded companies. Mineral and energy production Wyoming's mineral commodities include coal, natural gas, coalbed methane, crude oil, uranium, and trona. Wyoming produced 277 million short tons (251.29 million metric tons) of coal in 2019, a 9% drop from 2018. Wyoming's coal production peaked in 2008, when 514 million short tons (466.3 million metric tons) were produced. Wyoming has a reserve of 68.7 billion tons (62.3 billion metric tons) of coal. Major coal areas include the Powder River Basin and the Green River Basin. The boom for coalbed methane (CBM) began in the mid-1990s. CBM is methane gas extracted from Wyoming's coal bed seams. It is a means of natural gas production. There has been substantial CBM production in the Powder River Basin. In 2002, the CBM production yield was 327.5 billion cubic feet (9.3 km3). Wyoming produced of crude oil in 2007. The state ranked fifth nationwide in oil production in 2007. Petroleum is most often used as a motor fuel, but is also used in the manufacture of plastics, paints, and synthetic rubber. The Kelsey Lake Diamond Mine in Colorado, less than from the Wyoming border, produced gem-quality diamonds for several years. The Wyoming craton, which hosts the kimberlite volcanic pipes that were mined, underlies most of Wyoming. Wyoming produced 1.77 trillion cubic feet (50.0 billion m3) of natural gas in 2016, ranking the state ranked 6th nationwide in natural gas production. Major markets for natural gas include industrial, commercial, and domestic heating. Wyoming possesses the world's largest known reserve of trona, a mineral used in manufacturing glass, paper, soaps, baking soda, water softeners, and pharmaceuticals. In 2008, Wyoming produced 46 million short tons (41.7 million metric tons) of trona, 25% of the world's production. Because of its geography and altitude, the potential for wind power in Wyoming is one of the highest of any U.S. state. The Chokecherry and Sierra Madre Wind Energy Project is the