Despite once being noted as the hottest place on the planet (it lost the record to a Chinese desert back in 2004), Death Valley was well-known in the mid 1800s for its borax mine at Furnace Creek. The mineral is deposited through seasonal evaporation from the valley’s lake bed and was prized as an ingredient in many laundry detergents, cosmetics, photographic solutions and various industrial processes. While that particular mine only operated for 5 years, mining continued at various locations within what is now the national park up until 2004.
You can still find large mounds covered in the white mineral in the Furnace Creek area. They give the areas around them a distinct smell of cleaning products!
For the technically inclined...