Early mining companies were formed to channel Stanislaus River water to the gold diggings via elaborate canal and flume systems, which directly preceded the irrigation districts formed by farmers who sought a greater degree of river control. Starting in the early 1900s, many dams were built to store and divert water; these were often paired with hydro-power systems, whose revenues covered the high cost of the water projects. In the 1970s the construction of the federal New Melones Dam incited major opposition from recreation and environmental groups (documented on the Stanislaus River Archive), who protested the loss of one of the last free-flowing stretches of the Stanislaus. Although New Melones was eventually built, its completion is considered to have marked the end of large dam building in the United States.