By 1932, Lion Oil operated 441 service stations. In 1935, the company continued to expand with the purchase of the Arkansas properties of Marathon Oil, adding twenty-nine bulk plants and 375 service stations to its holdings. In 1939, Lion Oil became the first Arkansas corporation to be traded on the New York Stock Exchange (NYSE).
Lion Oil service stations became a common feature along roadsides in the South. At their peak in the mid-1950s, nearly 2,000 Lion service stations dotted the region. In the 1960s, this gave rise to the popular “Beauregard Lion” mascot in Lion advertisements. However, by the 1970s, Monsanto had integrated the company into its operations, and the Lion identity began to disappear. Monsanto slowly sold off many elements of the old company, shutting down the service stations, and employment dropped. In 1975, Monsanto sold the oil refinery to California-based Tosco. By this time, not even the refinery was referred to as “Lion.”