Gypsum Springs Formation is located in the Williston Basin. Gypsum is an evaporate mineral formed as a precipitate on the floor of shallow sulfate-rich lakes or tidal pools. Most commercial gypsum is a massive, white, finely crystalline rock, but large clear crystals of gypsum are often found on the surface where coals rich in pyrite are weathering. The crystals were bright and shiny in the sunlight.
Small quarries and plants, which satisfy local demands for gypsum products, have operated intermittently in Wyoming since 1890. The primary use for gypsum is in the manufacture of sheet rock wallboard. Two plants in the Bighorn Basin of northwest Wyoming mine gypsum and process it into wallboard at nearby plants.