The Big Bend reach extends for 20 km from approximately 1 km downstream of the mouth of Castle Creek (Bkm 149) to just upstream of the mouth of Negro Bill Canyon (Bkm 129). This sinuous to meandering reach (average sinuosity 1.5) occupies a deep (275 to 370 m), narrow (610 to 820 m wide), generally symmetric canyon that cuts across gently folded strata of the Navajo Sandstone, Kayenta Formation, Wingate Formtion, Chinle and Moenkopi Formations. The average gradient of this reach is approximately 0.05%. (Pitlick and Cress (2000) report an average slope of 0.1% for this reach, about 33% higher than estimates based on available US Geological Survey topographic data for this reach.) Big Bend reach vegetation cover...
