What is Borax?
Borax is part of a group of minerals called borates. These minerals can appear in several forms, including clear crystals, soft fibers, or chalky white powders. In the Death Valley region, borates formed through volcanic activity, hot springs, and groundwater moving through ancient lakebeds. Over time, water carried the minerals into the salt flats. Because the valley has one of the hottest and driest climates on Earth, evaporation concentrates these minerals at the surface, creating a white crust of salt, borax, and alkali that still coats parts of the valley floor today.
The Rise of Borax Mining
The story of borax in the Death Valley region began in the 1870s, when prospectors searched the desert for valuable minerals. In 1881, Aaron and Rosie Winters confirmed the presence of borax on a salt marsh using the “green-flame test,” a simple method where borax, when heated in a flame, burns bright green. This told them they had found borax, and they soon sold their claim to businessman W.T. Coleman.
Coleman built the Harmony Borax Works, the first successful borax refinery in the region. To move borax to the nearest railhead more than 160 miles away, he turned to the now-famous 20 Mule Team. These teams hauled wagons weighing up to 36 tons through scorching heat, across rugged terrain, and over mountain passes in a journey that took about ten days. The 20 Mule Team became a lasting symbol of the desert’s grit and ingenuity and is still one of the most recognizable icons of the American West.
Borax Today
In Death Valley National Park, borax history is preserved at the Borax Museum at Furnace Creek Ranch and at the ruins of Harmony Borax Works, where visitors can learn about the people and operations that shaped this industry. Today, borax continues to play an important role in daily life. It is used in the production of ceramics, glass, and fiberglass, and it also has applications in welding, metal refining, agriculture, and fire safety. On the household level, borax became famous as a natural laundry booster. In the late 1800s and early 1900s, families across America relied on borax to soften water and whiten clothes, a tradition that continues in many homes today through the well-known “20 Mule Team Borax” brand.