I need to update or add to this resource because there are now 3 separate recognized sub species of SMB.
Research suggests that most populations, including SE Kansas, MO, AR and OK are a mixed hybrid representation per DNA sampling.
OK is trying their hardest to keep the Wachita strain separate from the Ozark strain but in 2020 the hybrids were already confirmed present in at least 6 states, yet some states further north haven't actually performed much DNA testing yet.
I can say that from my research I've found documentation that provides some visual ques to ID. 1 is length of Jaw bone and where the actual bone extends in relation to the eye. 2, southern and southern/northern hybrids typically have 12-13 soft dorsal rays, the true Northern strain tends to exhibit mainly 14 soft dorsal rays, yet sometimes 13. So there is "some" over-lap that requires DNA testing to provide the answers. A Northern strain at 3lbs has a smaller gape than a southern 3lb fish.
Sorry to rant.. my life has revolved around this specific topic for a couple of years, it's hard not to talk out loud about it!