esshup summed it up... Finding a source for male only LMB would be a trick and many states and it sounds like yours is one of them doesn't allow the harvesting of bass during the spawn when amateurs have the highest % chance of correctly sexing bass... You may be able to call up a hatchery, explain what you are looking for and see if they can hand select male LMB for you. I suspect that would come at a high price tag though. LMB and SMB will cross, how common that is I really don't know. They are commonly known as "meanmouth" bass. I don't know for sure, but I am guessing the odds of male LMB crossing with female SMB would be lower than female LMB crossing with male SMB. If you could source male only LMB, stocking several a year could certainly help you in controlling your BG.