These data were compiled to better understand sedimentation patterns on the bed of the Colorado River in Grand Canyon National Park, and the way these patterns relate to suspended sediment grain size and concentration. These data were collected by the US Geological Survey Grand Canyon Monitoring and Research Center from 2000 to 2014, primarily using the "Flying Eyeball" underwater imaging system. This dataset is composed of over 50,000 samples, as part of 16 individual data tables from 16 research expeditions. On each expedition, grain size measurements were made in a grid-like pattern over short segments of the river. Each point sample includes mean grain size, geographic coordinates, date, and geomorphic setting.