These data describe the distribution and abundance of Hydropsyche, a widespread and diverse genus of net-spinning caddisflies, in the Colorado River Basin. Abundance data, measured as catch rates, were collected by citizen scientists using light traps. We subsampled Hydropsyche spp. from light trap samples collected throughout the Colorado River Basin and measured the lengths and widths of mesothoracic tibia and first tarsal segments. Samples and measurements were processed at Grand Canyon Monitoring and Research Center in Flagstaff, AZ.