Q. What is the limit on bass, and is it the same for largemouth and smallmouth? A. In Idaho, largemouth and smallmouth bass are lumped together simply as bass in the rule book. The bag limit and size restrictions depend on the water. For general rules waters, the limit is six bass, none under 12 inches. In quality bass waters, no bass may be kept until after July 1, and after that the limit is two, none between 12 and 16 inches. In waters managed for trophy bass, the limit is two fish, none under 20 inches. Check the rules brochure for the water you want to fish. If that water is not listed under "exceptions," then the general bass rule applies.