Waterfalls on the eastern side of Rocky Mountain National Park, Colorado, USA

We examined 30 waterfalls on the eastern side of Rocky Mountain National Park in Colorado, USA, to evaluate whether drainage area or bedrock properties as reflected in joint characteristics correlate more strongly with the location and characteristics of individual waterfalls. Longitudinal profiles tend to be more concave for larger drainages, to have a smaller proportion of total elevation loss in waterfalls, and to have vertical drops rather than angled or ramp waterfalls: we interpret these trends to indicate greater overall incisional capability for larger catchments. Shape of individual waterfalls and height of drop correlate more strongly with bedrock properties: waterfalls in bedrock lacking prominent vertical joints perpendicular to flow are more likely to have a single drop rather than multiple drops, and taller waterfalls correlate with more widely spaced horizontal joints. Waterfalls also noticeably correspond to resistant bedrock outcrops that form steep segments along hillslopes adjacent to the channel. We interpret these results to indicate that the location and characteristics of waterfalls along headwater streams in the study area reflect primarily a limited ability to incise through more resistant segments of the underlying bedrock.