They used to come in at the same time as the buck smallmouth. I'm pretty sure it is temp related among other things.
I used to be a smallmouth nut, so i would be in there form 46 degrees til they left.
We usually caught more rockies than SM, early on, and some of them were remarkably large. They also eat very well out of that colder water, but they get quite wormy when the water warms up, not worth the effort to me.
That time frame would be over now, but i'd wager a man could still scratch out a few. We would get the most of them on #7 shad raps in any color, but you could do very well with a small white twister under a casting bobber fast cranked.
Oh well, just some things that worked for me in the past.
It's an overlooked fishery to say the least, so you may do better than expected.
Good luck if you go after them, brother, and let me know how you do.