A series of aerial photographs were obtained for a nu¿e ardente produced by the February 8, 1976 eruption of the St. Augustine volcano, Alaska. The nu¿e ardente reached a maximum velocity of 50 m s-1 while descending the steeper (~1:3) slope of the volcano. It later slowed to a velocity of 6 m s-1 as it traversed the gentler slope (~1:25) at the base of the volcano, where it formed a deposit. The nu¿e ardente appeared to originate with the collapse or penetration of a newly formed dome, rather than the collapse of a vertical eruption column. Fluidization by fine particles in the nu¿e ardente probably contributed to its mobility.