Bridge Canyon Dam, or Hualapai Dam, was a major but never built proposal for the lower Grand Canyon in northern Arizona. First advanced in the 1920s and studied most intensively from the early 1950s to 1968, it was linked to the Pacific Southwest Water Plan, which would have used hydropower from Bridge Canyon and Marble Canyon dams to pump Colorado River water toward central Arizona. The planned structure and reservoir would have transformed a long stretch of the canyon, prompting strong opposition over damage to natural features, evaporation, sediment, and limited storage. Its eventual defeat became a landmark conservation victory in Grand Canyon history.