An alluvial fan sequence in the southern Arrow Canyon Range, Nev., consists of an earlier mudflow and a younger stream deposit. Particles of both phases have an exponential decline in size away from the source area. The mudflow has a steeper curve of particle-size decline and a lower correlation coefficient than the stream deposit. The stream deposit is largely the result of reworking of the older mudflow, but has a consistently lower particle size caused by weathering and splitting of the particles. A general increase in the rod- and disc-shaped pebbles downstream is due to transportation in traction and suspension, respectively. Fan head entrenchment is the result of a change from mudflow to stream conditions and the development of a new fan profile.