I haven't fished out there this year but the sauger aren't hard to find when they are running -- and they should have started. Generally they are caught on the edge of currents in 8 - 15' of water. If you are catching numbers of whites and stripers I would say you are fishing in more current than sauger prefer. Further, sauger are pretty light sensitive so on bright days they bite far better early or late. Techniques vary from vertical jigging with jigs / minnows to casting jigs from 1/8 to 3/8 oz heads depending on depth/wind/current. Sauger hang to the bottom so keep your lures down. As far as McAlpine area goes you can catch them from Sand island to the lower gates to the duck pond to the big eddy in front of the interpretive center and many places in between. Move around and find where they are.
kc