LOOP (Louisiana Offshore Oil Port) offloads crude oil from tankers, stores it, and routes it to pipelines and refineries along the Gulf Coast and the Midwest. It is also the storage and terminalling facility for the MARS pipeline system and its supply of offshore Gulf of Mexico crude oil. Oil is stored in eight underground caverns leached out of a naturally occurring salt dome. These caverns are capable of storing about 50 million barrels of crude oil. The company is owned by Marathon Ashland Pipe Line, Murphy Oil, and Shell Oil. In addition to other services LOOP has an above-ground tank farm made up of six 600,000 barrel tanks.