(Francisco Kjolseth | The Salt Lake Tribune) The Bonneville Salt Flats, comprised of mostly sodium chloride that forms a hard, white salt crust and home to numerous land speed records, are covered in nine inches of water, forming a shallow lake on Friday, Jan. 27, 2023. With nowhere for the rain and snow melt to go, precipitation slowly evaporates throughout the year to restore the flat's delicate salt layer.