The Negro Bill reach extends for 5 km from just upstream of the mouth of Negro Bill Canyon (Bkm 124) to the US 191 highway bridge on the northeast edge of Moab Valley (Bkm 129). This moderately sinuous reach (average sinuosity - 1.3) flows within a deep (90 to275 m deep), narrow (245 to 460 m wide) asymmetric canyon that cuts across very gently dipping strata (mostly sandstones) of the Kayenta and Navajo Formations. This reach marks the upstream limit of a continuous series of very low gradient reaches that extends downstream for almost 116 river kilometers to the upstream limit of Cataract Canyon. The average gradient of this reach is about 0.03%.
Shrubs are the most prevalent cover type in this reach with tamarisk (9%), willow (8%) and native xeric (4%). Non-native herbaceous species are common here (9%), though they are not associated with agricultural activities. Riparian trees are present but not abundant (cottonwood 1%, Gamble oak 3%). Ownership in the Negro Bill reach is mostly State (83%) with some BLM (15%) and a small amount of private (2%).
