Consistent surveying of bed elevations in natural channels containing gravel and cobble substrates is subject to measurement error if a leveling rod is placed indiscriminately between or on top of individual particles. The influence of surface microtopography decreases with increasing leveling rod base diameter, while the influence of bed form topography increases. Field tests were performed to identify a rod base diameter that minimizes these survey errors. A leveling rod base diameter of 127 mm (5 inches) is suggested to be most appropriate for consistent bed surveys. ¿ 1999 American Geophysical Union