Stripernut gave you a lot of good info there. I seriously would not attempt to start learning how to catch Alewives on Cumberland right now. I would opt for cast netting gizzards in the backs of the creeks but that can be a very messy mission with a good chance of tearing your net.

As deep as they are and with the possibility of them being schooled up pretty good I would suggest shiners or spoons. Find a school and drop a heavy spoon (at least an 1.5 oz) straight down to the bottom. Then reel straight back up at a quick steady pace. You'll need to be able to get something you troll down to around 70 ft right now so it would need to be down riggers or a deep diving disc like the slide divers.