The Pacific Coast Borax Company was a United States mining company founded in 1890 by the American borax magnate Francis Borax Smith, the Borax King.The roots of the Pacific Coast Borax Company lie in Mineral County, Nevada, east of Mono Lake, where Smith, while contracting to provide firewood to a small borax operation at nearby Columbus Marsh, spotted Teels Marsh while looking westward from the upper slopes of Miller Mountain where the only nearby trees were growing.

The Pacific Coast Borax Company was a mining company founded in 1890 and based in Los Angeles, California. It was the first large-scale mining operation in the United States to focus on borax, a mineral used in a variety of products, including detergents, cosmetics, and glass. The company was founded by Francis Marion "Borax" Smith, who had previously worked in the borax industry in the western United States.

The Pacific Coast Borax Company was the first to use large-scale mining and processing techniques to extract borax from the ground. Smith's innovative techniques allowed the company to quickly become the largest borax producer in the world. The company's success was due in part to its use of the "20-mule team" to transport borax from the mine to the processing plant. This method of transportation was far more efficient than the traditional horse-drawn wagons. The Pacific Coast Borax Company was also a pioneer in the use of marketing and advertising to promote its products. The company's most famous campaign was its "20 Mule Team" advertising campaign, which featured a team of mules and a wagon carrying a load of borax. This campaign was so successful that the image of the mules and the wagon became an iconic symbol of the company.

In addition to its mining operations, the Pacific Coast Borax Company also operated a number of other businesses, including a hotel, a theater, and a retail store. The company also produced a number of products, such as laundry detergent, soap, and glass.

The Pacific Coast Borax Company ceased operations in the mid-1900s, and its assets were purchased by the U.S. Borax and Chemical Corporation in 1962. The company's legacy, however, lives on in the iconic 20-mule team image, which is still used in advertising today.