Hey Gravy, I was going to post on the other thread but this one will do. I can only comment on places I have dove.
Square Lake, by Stillwater- this is a training tub lake that used to have good viz but lately it is only moderate. Kinda fun to swim from training platform to training platform. There are about 4 sunken boats, a canoe, a tail section from a small plane, and a toilet on one platform and a chainsaw on another. There are ropes leading from one to another. the sunfish can hear a snail shell cracking and come over to be fed from your hands. there is a bullhead living in the toilet tank.
Minnetonka- has some bigger wrecks (for inland lakes) but they are 40' to 70' deep. There is even a twin outboard cabin cruiser with the trailer still attached to it sunk there. Summer diving there kinda sucks as there are so many boats that don't know what a dive flag is.
Whitebear Lake- not bad viz but you need a boat to get out as it is shallow for ever.
Calhoun- not bad viz. kinda muddy bottom. interesting bottom contours. some neat things to find in the mud on the bottom for a city lake.
Forest Lake- poor viz in summer and 5' viz in winter. sunken fiberglass boat, sunken complete fish house. rumors of a p51 mustang still in the lake somewhere from 1954.
Spectacle Lake Isanti County- good viz. couple sunken boats, sunken lifeguard tower. lots of sunfish.
Green Lake Isanti County- poor viz in summer and lately 8' viz under ice. Viz has been as good as 20' there under ice a couple years ago. 2 sunken boats.
Fish Lake Chisago County- poor viz 5' in summer but ok to get wet in.
Mille Lacs Lake- never dove it in the summer but winter I have dove it a half dozen times. up to 30' viz in winter. lots of anchors and stuff to find there. big lake so you could dive every day and never see the same thing twice if you wanted to.
Crosby Pits- - - this area contains many many iron ore pits and you must dive here but not right away. once you dive here you will be spoiled and won't want to dive in the other 12,000 lakes in our state. Viz is generally awsome at 30'+. most have submerged trees around the perimeters that are fun to swim around. most of them have at lease two sunken vehicles in them and a boat each I suppose.
- Huntington mine - Crosby- My favorite pit of them all! this one has a few vehicles in it and a boat. Last summer some people I know found a freshly stolen van and a dump truck at 105' deep there the day I was there with another dive buddy. We went back there several times and recovered some of the stolen items for the Crosby Police Department. There is also two beaver lodges on this pit that hold a lot of fish. There is a vertical mine shaft there that starts at 8' deep and goes to??? There is at least one horizontal drift that goes from one mine pit to another adjacent mine pit at about 110' deep. DON"T go in there although I know some who have. It is very unstable and tangley.
-Alstead South mine - Crosby fun pit too with 3 sunken cars and atleast one beaver lodge.
-Portsmouth Mine - Crosby-sunken snowmobile and mining artifacts kinda fun for a night dive.
- Louise - Crosby- did my Divemaster checkouts there. haven't dove there since but nice pit.
Lake Superior- Kind of a long drive but really worth it. Madeira Wreck is a nice shore entry dive. Hesper wreck also is a nice shore entry dive. Gooseberry Falls has an anchor from a wreck but no wreck was found yet and this is a nice couple of shore dives. There are many many many places to dive in Superior but most need a boat to get to. and its almost always cold 34 -44 degree water but sometimes it stays as warm as 65 degrees at 80' deep (that is not the typical deal though) Lots of people dive there with a 7 MM but more enjoyable in a dry suit I think.
So that is the short list. The big thing with diving in Minnesota is don't get worked up about not having viz over 10'. good viz is over rated and I have more fun diving in some lake where divers haven't been as there is more loot in those.
I really think you should log into WWW.MNSCUBA.COM to get better info about diving in MN. There is a search enging on that site that will lead you to some of the best diving in the state. Minnesota has a dive legend living there also named Bill Mathies who owns the "Minnesota School Of Diving" in Brainerd and also a dive shop in St. Cloud. Bill has been around since the beginning of PADI. His PADI certification number is 79. He has tons of info about the Crosby pits and other sites. We just lost the Last NAUI dive shop 2 years ago (Smith Diving) that had been in business since 1969. I took few NAUI classes and I think they are more in depth (no pun intended) than PADI.
If you get bored look at some of my videos I have taken in local Minnesota lakes on my youtube channel: http://www.youtube.com/user/scubapony?feature=mhum
or check out our dive teams Facebook page for more photos at: http://www.facebook.com/pages/Isanti-County-Dive-Team/139087026162913