Oxy THUMS comprises four man-made islands in Long Beach Harbor, California. THUMS encompasses a portion of the giant Wilmington field, which was discovered in 1932. When Oxy acquired THUMS in 2000, it retained the name derived from the original consortium of operators: Texaco, Humble, Unocal, Mobil and Shell.

Under the terms of a partnership agreement between THUMS Long Beach, the city of Long Beach and the state of California, THUMS was designed to blend in with the surrounding coastal environment. Drilling rigs and other above-ground equipment are camouflaged and sound-proofed, and wellheads and pipelines are located below ground to ensure that the islands enhance the appearance of both harbor and skyline.

The THUMS islands were named after the first four astronauts who died in the line of duty in the early years of the U.S. space program. Freeman encompasses about 12 acres, while Grissom, White and Chaffee cover approximately 10 acres each.The islands were constructed using 640,000 tons of boulders and 3.2 million cubic yards of sand. Weighing up to five tons each, the boulders rest on the shallow harbor bottom and form a perimeter for each island. An elaborate irrigation system keeps more than 700 palm trees alive in the unusual island soil. Abstract sculptures and waterfalls, some as high as 45 feet, are offset by attractive landscaping and colorful night lighting.

THUMS' unique combination of production functionality, visual appeal and environmental safety has garnered the facility dozens of design and engineering awards from local, state and national organizations. The first oil operation to inject reclaimed city water to help maintain reservoir pressure for waterflood recovery, THUMS received an Environmental Award from Hart's Oil and Gas Investor magazine as Best in the Pacific for the use of reclaimed water in its water injection program.