Each zone on the map represents the approximate date (to the nearest week) when smallmouths begin to spawn. Actual dates in your immediate area may vary due to local water temperatures and weather conditions. Note that the dates listed apply to large, public waters, and remember that bass will spawn earlier in smaller or shallower water bodies. Spawning activity in rivers is highly dependent on upstream weather conditions, and the spawn may occur earlier or later than in nearby lakes.
How long the spawn lasts also depends on the size and form of the lake. Spawning may occur in shallow, dark-bottom bays two to three weeks earlier than in the main lake. Similarly, river bronzebacks may spawn in shallow backwaters as much as a month earlier than in the river itself. Exactly where smallmouths spawn varies among lakes and reservoirs, but two constants are observed year after year, regardless: 1. Spawning areas are located outside of flow areas; and, 2. Beds are usually made on gravel or adjacent to rocks. They can be very shallow, even in clear water, and conspicuous, or they can be deeper and completely out of sight.