There is a link to maps right on the home page of this site, or you can go to the DNR site and they have a link to lake maps, you can find out most things about any lake. Some of the maps are from as far back as the 40's, but it will give you a good starting point. You'll see on the left side where it says, "back to My fishing pals" click on that and it will take you to the home page.
i went on that minnesota lake maps and it just has most of the bigger lakes in minnesota. It said if there wasn't a map for a lake someone is looking for they will post it? I don't know if the admninistrator of the site takes care of something like that?
It is to the DNR Lake Finder that the previous post was talking about. Just type in the name of the lake you want and county and it will give you a list of the lakes. It will provide a lake map and the most recent survey results and stocking reports. Like mentioned some of the maps are pretty old but they are still fairly accurate for the most part. The drop offs, points, islands and rock piles tend to stay in the same place over time.
One thing to consider on most lake maps is that if they were done a few years ago the depths might be a little off becuase of our low rain fall amounts in the past few summers. I know when I was up on Mille Lacs the last two winters I had to subtract 2 feet from all the depths listed on my map.