Alliance Resource Partners is a diversified producer and marketer of coal to major United States utilities and industrial users. ARLP was founded in 1971 as MAPCO Coal, and it has since grown through acquisitions and internal development to become the sixth-largest coal producer in the Eastern United States. Coal is the energy source used by utilities to fuel more than 50 percent of the electricity generated in the U.S. each year. More than 70 percent of Alliance Resource s sales tonnage is dedicated to electric utilities that have long-term contractual relationships with the company. Headquartered in Tulsa, Okla., Alliance Resource Partners has offices in Lexington, Ky., and Denver. The company has a workforce of more than 2,000 employees.