A morphometric comparison of valleys has been made for the Ben Ohau Range in the central Southern Alps of New Zealand. The range is undergoing rapid tectonic transport and uplift. First, the sequence of topographic transitions caused by a change
in dominant process regime, from fluvial to glacial erosion, is described. Then, the time-scale of change is evaluated. Finally, observations are related to the hypothesized relief development implicit in existing tectonic-isostatic models of alpine uplift.