A few weeks ago I posted some photos of a lamprey being killed/eaten by a water snake. Some concern was expressed by some (and held by me) that it was a Sea Lamprey. Obviously, that particular lamprey would be an unwanted inhabitant; do a quick Google on Sea Lampreys in the Great Lakes and you'll see why.
I contacted the Parks Department and the Missouri Department of Conservation about it just in case it was a Sea. They got back with me after seeing the photos and definitely ruled out Sea Lamprey; it is likely a Silver or Chestnut, both are common in the Mississippi system. So, breathe a sigh of relief with me (and MDC) that the Sea Lamprey has yet to show up around here.