This is a picture that I took on my digital last spring. It is the only one I can find, except some when I was even farther away from the lake, and you can't make anything out (I'm not a photog)
This was after the wind changed directions. Originally the wind was out of the SW, and it made the waves line up real nice as they wrapped around the pier (photo is of the north side of the pier), but I didn't take this picture until the wind turned West with a little North in it.
(as far as 3 foot slop) If you look half way down the pier, you will notice a wave coming about 3-4 feet above the top of the pier (it isn't breaking against it, if you look close you can see that it is rolling against it, there wasn't enough north in the wind to send it into the pier) And as far as the smaller waves go, those aren't really waves, that is just mess between the sets. The larger wave in the middle is obviously a survivor of the wind turning west and weakening the waves.
The drop from the pier down to normal water level (during flat conditions) is about 6 1/2 - 7 feet (on average, and for the last year and the year before the water levels in the lakes were down) So, this wave has to be at least 8 foot. You can reference it against the lighthouse in the back (they are generally pretty tall) The waves in this pic are Not pretty, but like I said, I was surfing when the waves were good, I just took a picture after I came out and went back to my truck. Just to give you an idea that the size is definately there, and they get more size than this, this is a spring swell which sucks here (warm wind blowing against cold water, takes a lot of wind), (and it isn't all 3 foot days like what has been captured in most films about it).