It may not be the biggest, but Murphy USA is flexing its muscles in the US gas station market. Murphy USA (a former operating unit of Murphy Oil) markets refined products through its network of branded gasoline stations and convenience stores customers and unbranded wholesale customers in 24 southern and midwestern US states to more than 1.6 million customers. The company's more than 1,300 retail gas stations (more than 1,100 of which are in Wal-Mart Supercenter parking lots) sell gas under the Murphy USA brand. It also operates more than 200 Murphy Express locations.