The bummer is only on the ski and climbing side of things. Creeking in MN is going to surprise you. I got my start kayaking in Duluth (heart of creeking country) and Craven is somewhat correct about the run off. My paddling journal indicates we are usually on the creeks by the first week of April and finish up around the last week in May for a normal year. The usually get a couple stretches of good rain in June that allow for good class V boating. You definitely develop an off-the-couch class V attitude in the North country. If you're into creeking this is going to be very different style than most CO boating (more like OBJ type style). Low volume, lots of big slides, and vertical drops. The entire North and south shores of Lake Superior are packed with quality creeks. Every 5 mins you'll run into another... you can get 3 high quality creek runs done in one day if you have the energy.
(Myself) Lester River... within the Duluth, MN City Limits
Check my blog for tons of pics, videos, descriptions of creeking in Northern MN: www.adventuresofburgess.blogspot.com
. During summer it's pretty rough. Boating in the near the Twin Cities is pretty scant and consists of mostly Class III. The nearest whitewater park is in Wausau WI. Usually we had head 8 hrs up to Sturgeon Falls Manitoba for amazing playboating on the Winnipeg river (65,000 cfs... no tows, eddy accessible!). You'll get a few releases on the Lower St. Louis for some mid summer Class IV/V.
In terms of river descriptions... AW has little detailed documentation of MN boating for the majority of creeks and certainly not enough to get you out. The best/only guidebook is Northwoods Whitewater
, it's largely accurate though slightly outdated.
In terms of MTB... there's a race every weekend! It's huge in the state and tons of riders. But get used to muddier conditions. I'm most familiar with the Duluth area which has some more technical riding as there is alot more bedrock and elevation changes to suit such riding. Check out the COGGS (Cyclists of Gitchee Gumee Shores) website...tons of trails (COGGS - Cyclists of Gitchee Gumee Shores
). That's my two cents for starters.