A river doesn’t just carry water - It carries life. To smallmouths and all other fish species residing in them, a river’s water level and flow rate will dictate their seasonal migrations, locations, habitats, feeding, and all other variables to the fish-catching formula you could think of!   Unlike the better consistency and predictability of lakes, rivers are prone to all sorts of rapid changes that include water level, temperature, and clarity. Fish species are also constantly on the move. Current is what defines a river and is complex for many anglers to solve. Rivers will easily defeat anglers, especially those who’ve failed to interpret and calculate water levels, stream-flow rates, and gauge heights. Mobile Apps such as RiverCast and USGS Mobile Water Data can be trusted for water level study to determine where and when to go without ever having to set foot into the river before arriving. These apps are accurate, but understanding a river’s characteristics and how smallmouths themselves react to frequent changes are ultimately the best learning tools.  Smallmouths live the good life in rivers with a healthy current flow. Compared to mo