Yup, I've got a few idea...
The best place to start is the dam. There is parking, and the hike to the water is relatively short. There are several adequate places to get into the water.
There are a couple of things you might want to know about the underwater topography. First, the dam you see is actually the SECOND to be constructed, and the first one is still underwater about 40 yards upriver. It was a stone dam, and it trapped decades of silt behind it. Therefore, when you enter the water, try to locate the old dam (lots of rocks) and about 25 feet down, and you will be able to follow it all the way across the lake to the other side. However, remember that the water between the two dams is nearly 100 feet deep (at the deepest point). The old dam does make a pretty good wall dive, if you can stand the theremoclines, which tend to be pretty sharp and extreme in this little lake. Oh, and one other note...about halfway across the old dam your compass will go wacko...evidently there is some metal or other magnetic anomaly that will throw it WAY off. Once you get to the other side, follow the shore to the right and there are some pretty good walls and what we now call the "clear valley". Get under the thermocline, and the vis opens up a LOT...we were able to see about 50 feet on our last visit there, and that was during a pretty murky algae bloom.
If you follow the shore to your right upon entering, you'll pretty much follow a shallow wall and eventually run into "the forest"...just water plants, but they home for a LOT of fish.
Toward the middle of the lake, the bottom is pretty silty and tends to be about 20-30 feet deep, pretty flat, but sometimes you see some good fish.
After your dives, you might want to visit the Meers Store, which is actually a pretty interesting cafe. Try the buffalo burger...very good! To get there, go on into the wildlife refuge and take the cutoff for Meers (there is no town...the cafe is the only thing there).
Have fun! I sure wish I could go, but alas...work. Let me know how it goes and perhaps we'll be able to dive there together sometime.
Bill