The UVR corridor is a diverse riverine ecosystem in central Arizona (see Chapter 1). Since European settlement, it has witnessed many events such as droughts, floods, construction of Sullivan Dam, groundwater withdrawals, cattle grazing, mining, nonnative fish introductions, native fish extinctions, and urbanization that are not fully understood. Geologically, the UVR displays a wide array of formations of spectacular color and variety; the landscapes vary from open valleys to narrow and deep canyons. Several publications have described the Verde River (Wirt and Hjalmarson 2000; Blasch and others 2006), yet few provide pictorial descriptions of historical and existing conditions. Oral accounts offer different glimpses of purported historic conditions (Byrkit 1978). For the most part, descriptions of the Verde River are largely limited to the Middle Verde River and the Lower Verde River. The UVR is distinct from the former sections due to the smaller character of the landscapes, yet it is unique in many attributes.