The classical hydraulic jump, which is a hydraulic jump formed in a horizontal, smooth, and prismatic laboratory flume, has often been used for estimating hydraulic and morphologic characteristics of mountain river channels. However, most studies utilizing classical hydraulic jump relationships have neglected the role of aerated flows and jump types prevalent in natural systems. By developing a methodology to survey, digitize, and visualize air concentrations for jumps in bedrock rivers, we present new data for submerged jumps and sloping jumps in a bedrock step-pool channel. As with laboratory research, our results indicated peak, mean, and local air concentrations of natural jumps were skewed by submergence of the jump roller beneath the free surface. However, unlike laboratory research, cross-stream variations were significant for both jumps, varying up to 20% across the jump width. Traces through each jump thalweg also indicated the classical hydraulic jump was a poor analogue for estimating surficial air concentrations.