 The glacier released a particularly large mudflow on October 2–3, 1947, when heavy rains melted and eroded the lower part of the glacier.The meltwater transformed into a 14 billion ft3 (40 million m3) mudflow replete with large boulders up to 13 feet (4 m) in diameter.The flow buried Highway 706 in 28 feet (9 m) of sediment and watery debris.