Clayton Propane, 22662 US Highway 270, Woodward, OK 73801, US

With 2005 revenues of $1.9 billion, Terra Industries is a leading international producer of nitrogen products. The company can annually produce: 4.6 million tons of anhydrous ammonia, the basic ingredient for most nitrogen fertilizers and many industrial products; 4.3 million tons of urea ammonium nitrate solutions, a versatile nitrogen fertilizer; 1.8 million tons of ammonium nitrate, a nitrogen fertilizer that is popular in the southeastern United States; 260,000 tons of urea, the world's most widely used nitrogen fertilizer; and 40 million gallons of methanol, an ingredient in oxygenated fuels and a feedstock for other chemical processes. Terra Industries operates an ammonia, urea ammonium nitrate and methanol facility in Woodward, Okla.