There is always going to be fish that spawn earlier and later than the "main" spawn. On a big lake like Clear Lake this is especially true because the water temp and conditions vary throughout the lake. On a small lake like Shadow Cliffs I would expect that most of the fish would spawn on the "main" spawn but even then you'll have plenty of fish before and after. I sometimes wonder if the same fish spawn more than once during the spring. I don't know the answer to this, does anyone know? If you have a lake that is pretty clear you can watch this unfold during the spring months. If the lake is muddier like San Pablo or Coyote it's harder to see what is going on.