LOOP was organized in 1972 as a Delaware corporation and converted to a limited liability company in 1996. LOOP is a joint venture of Marathon Pipe Line LLC, Shell Oil Company, and Valero Terminalling and Distribution Company.LOOP is the only port in the U.S. capable of offloading a wide range of vessels including Ultra Large Crude Carriers (ULCC) and Very Large Crude Carriers (VLCC) down to Medium Range (MR) Tankers.

The port consists of three single-point mooring buoys used for the offloading of crude tankers and a marine terminal consisting of a two-level pumping platform and a recently replaced three-level control platform. The Clovelly Hub is located twenty-five miles inland, and is connected to the port complex by a 48-inch diameter pipeline. The Clovelly Hub provides interim storage for crude oil before it is delivered via connecting pipelines to refineries on the Gulf Coast and in the Midwest.The oil is stored in eight underground caverns leached out of a naturally occurring salt dome. The caverns are capable of storing approximately 60 million barrels of crude oil (a barrel of oil is equal to 42 U.S. gallons). There are three dedicated caverns for streams coming in from the deepwater Gulf of Mexico; two for Mars and one for Thunderhorse. In addition, LOOP has an above-ground tank facility consisting of fifteen 600,000 barrel tanks. Current construction will expand the tank facility by seven 375,000 barrel tanks.

Three pipelines connect the Clovelly Hub to refineries in Louisiana and along the Gulf Coast. LOOP also operates the 53-mile, 48-inch pipeline that connects LOOP to LOCAP Terminal at St. James, Louisiana. The LOCAP Terminal is connected to Plains Terminal, NuStar Terminal, Sugarland and Capline. Capline is a 40-inch pipeline that transports crude oil to several Midwest refineries.