Dams & river regulation have become an integral part of 20th-century landscape & livelihood.Virtually every river in the lower 48 states is now regulated by dams, locks, or diversions. This reportillustrates the downstream consequences of dams & explains the basis on which rivers can be scientificallymanaged. Following a look at a free-flowing river - the upper Salt River of Arizona - & its natural cycles offlow & sediment, 6 regulated rivers are examined. Each of these rivers - the Snake, Rio Grande,Chattahoochee, Platte, Green & Colorado - highlights a particular use of a dam or a particular downstreameffect.