This post is part of our Big Company, Small Town series, featuring large companies and the small towns in which they are headquartered.

If you like to save money on gas and live near a Wal-Mart in the Southeast and Midwest, chances are you are filling up these days at stations operated by Murphy Oil Corp. (NYSE: MUR), which is headquartered in the small town of El Dorado, Arkansas.

Those Murphy USA gas stations, located in parking lots of Wal-Mart Stores (NYSE: WMT), are just a small part of Murphy's many energy-related businesses. Murphy Oil is a giant, publicly-traded oil and natural gas exploration and production company with operations as far afield as Malaysia and Ecuador. Much of its U.S. drilling and refining is done off the shores of Louisiana, and some of that equipment was damaged during Hurricane Katrina. Sales in 2007 were more than $18 billion and the stock is up 60% in the past year. The company was recently ranked No. 134 in the Fortune 500 (to put that in perspective, Google is ranked 150 and Nike 153).

Corporate headquarters to all this (as well as a timber company that was spun off from Murphy in 1996), is El Dorado, population of 20,000. A boom town in the 1920s when oil was discovered, El Dorado has a colorful history and currently boasts summertime reenactments of a Wild West style gun fight on the courthouse steps, as well as a historic "haunted" theater. The town participated in the federal "Mainstreet" program, which provides grants for restoring historic downtowns, suggesting that the downtown was once in rough shape, but has since been prettied up.