ABSTRACTNear Ash Hill in the Mojave Desert, California, there is an impressive channel that is cut in bedrock. The channel is in a passthrough which Lake Manly, the pluvial lake that occupied Death Valley, could have overflowed. Indeed, the channel hasbeen attributed to such overflow. The pass, however, is 500m above the highest shorelines of Lake Manly in Death Valley,and evidence from cores from dry lakes on either side of the pass does not support the overflow hypothesis.Despite its size, new field observations suggest that the channel was actually eroded by local runoff. Water from severaltributaries collects into a single channel at this point, and the resulting discharge is apparently sufficient to cause retreat of aknickpoint from the downstream edge of the basalt flow into which the channel is cut. 1998 John Wiley & Sons, Ltd. Earth surf. process. landforms, 23, 377–384 (1998) KEY WORDS : Lake Manly; Death Valley; California; pluvial lakes INTRODUCTIONPluvial lakes occupied closed basins in the western United States repeatedly during the Pleistocene. The largestof these were lakes Lahontan and Bonneville (Gilbert, 1890; Morrison, 1964; Benson et al ., 1990; Reheis, 1996)(Figure 1). Although much smaller, Lake Manly in Death Valley (Blackwelder, 1933, 1954; Hooke, 1972;Hooke and Dorn, 1992; Li et al ., 1996; Roberts, 1996) still had a surface area of over 3000km