The robust fishery science literature— beginning with the “Plan for Analyzing and Testing Hypothesis” (Marmorek et al.1998) in the 1990s and continuing to the 2020 report “Achieving Productivity to Recover and Restore Columbia River Stream-type Chinook Salmon (Petrosky et al. 2020)—documents the necessity to achieve an average 4% smolt-to-adult return (SAR) survival in order to recover Snake River (Idaho) salmon and steelhead.