The Mojave River has two well-recognized bedrock constrictions: the Upper and Lower Narrows, located near Victorville in California. The constrictions occur where the river’s channel is narrowed because of resistant bedrock formations, which force the river through narrower gaps.
Upper Narrows: Above Victorville, the Upper Narrows is a reach where the Mojave River is cut through bedrock, making the channel narrower. This natural constriction allows the upwelling of groundwater that creates perennial flow in this reach of the river.
These areas have traditionally been used as recreational campsites and as points of water supply, such as was done at Lane’s Crossing just north of the Lower Narrows.
California’s Department of Water Resources
Lower Narrows: Downstream of the Upper Narrows, the Lower Narrows forms another place where the river is in contact with bedrock, creating a similar narrowing of the channel. This contraction also forces groundwater to surface, therefore maintaining a perennial flow in this area. The Lower Narrows is a significant landmark on the Mojave River and a crucial part of the river’s unique hydrology.
Department of Water Resources, California
These bedrock narrows are very important to the hydrology of the Mojave River, as they create perennial surface flows within an otherwise intermittent river system. The permanent water supply in these reaches maintains relatively diverse riparian habitats and has traditionally supplied resources critical to human uses within the region.