Data from the 1998–2002 resurveys of the Marble Canyon and Bridge Canyon dam sites in Grand Canyon National Park

These data were collected as part of a U.S. Geological Survey effort to resurvey the Marble Canyon and Bridge Canyon dam sites on the Colorado River in Grand Canyon National Park. The objective of our study was to resurvey these dam sites to document the changes in sediment storage that have occurred since the original 1940s–1950s Bureau of Reclamation surveys. The data in this release are the topographic data collected during the 1998–2002 resurveys, points digitized from original 1950s Bureau of Reclamation maps, and grain-size analyses of bed-sediment samples collected in 2002 at the Bridge Canyon dam sites. The resurvey data were collected along Colorado River at the Marble Canyon dam sites on September 19, 1998, and May 13, 2000, and at the Bridge Canyon dam sites on November 9–12, 2002. The bed-sediment data were collected at the Bridge Canyon dam sites on November 10–11, 2002. The resurvey data were collected by the U.S. Geological Survey using a total station, prism backsite, survey rod with prism, and single-beam sonar. The bed-sediment data were collected by the U.S. Geological Survey using a pipe dredge. These data were used to compute changes in sediment storage and can be used in future resurveys to document future changes at the Marble Canyon and Bridge Canyon dam sites.