Kelso Dunes, also Kelso Dune Field, largest field of eolian sand deposits in the Mojave Desert. Region protected by / within Mojave National Preserve. Dune field covers 45 square miles (120 km2), includes migrating dunes, vegetation-stabilized dunes, sand sheets, and sand ramps. Tallest dunes to 650 feet (200 m) above the surrounding terrain; composed predominantly of light-colored quartz and feldspar, most likely eroded from the granitics of the San Bernardino Mountains to the southwest. Notable for the phenomenon known as singing sand, or "booming dunes". Sand sliding down the face of steep dunes generates a low-frequency rumble that can be both felt and heard. San Bernardino County, CA.