Rio Grande Silvery Minnow (RGSM) are currently constrained to only 5% of their historic range, and their persistence is threatened by highly altered and impaired habitat conditions (Bestgen and Platania 1991). These habitat conditions have resulted from reduced spring and summer flows due to natural variability and anthropogenic water development and extraction, which have resulted in substantial geomorphic changes (Swanson et al. 2011). Successful conservation of this endangered species will require determination of how available flows can be managed to provide conditions supporting growth, reproduction, and survival of RGSM within and across a variety of water years. Previous research has identified that years with large spring high flow events and years with higher summer base flows support greater densities of RGSM during fall surveys (Dudley and Platania 2007; Archdeacon 2016; Walsworth and Budy 2021). However, given that years with large spring high flows also tend to have greater summer base flows, it remains unclear whether spring or summer flows (or both) are more critical to successful conservation of RGSM.