While out pheasant hunting this past weekend I ran across a new type of Minnesota public hunting land that I had never seen. These new tracts of land are called "Aquatic Management Areas" (AMA) and sound like they are similar to WMAs in that they are open to public hunting, but are meant to protect some critical habitat for aquatic life in cold water stream. The one that I know of can be found in this area on openstreetmap.org. Now looking at the map and from being in the area the AMA is just to the north west of the Buttermilk Run WMA on the other side of Murray County Rd 38. There is a stream that runs through it to Armstrong Slough. It is bordered on the north and south by farmland. For a map that show the AMA in some detail (as I have been unable to find any detailed maps showing where these are) you can kind of make out the outline on this map from google maps which is an aerial view of the general area. The one nice thing about AMAs is that their signage is similar to that of WMAs in that they are both the yellow signs and it is easy to confuse them while driving down the road, but this is fine as they are both open to public hunting.
Currently the MN DNR has a 25 year plan for acquiring an additional 1500 miles of cold water streams. The current plan is running from 2008 to 2033 and additional details can be found here from the MN DNR in their "AMA acquisition report" which was published in October 2007. If you do not have a PDF reader on your computer the MN DNR also offers a text version of the "AMA acquisition report".
Hopefully I will be able to find some more information on these areas, but in the mean time I encourage you to add any that you find to the openstreetmap.org project as anyone can edit this map.