Pacific Coast Borax Company - U.S. Borax

In 1956, the Pacific Coast Borax Company merged with United States Potash Corporation to form U.S. Borax, which itself was acquired by the Rio Tinto Group in 1967. As a wholly owned subsidiary, the company now is called Rio Tinto Borax and continues to supply nearly half the world's borates. It operates the largest open-pit mine in California next to the company town of Boron, in the Mojave Desert east of Mojave, California.

The Trona operation became part of Searles Valley Minerals.