The Minnesota State Parks system has announced that starting Wednesday March 28th, reservations for arrival dates through July 21, 2012 can be made.
Once the system goes live, reservations can be made at mdnr.gov/reservations or by calling 866-857-2757 (TTY 952-936-4008).
Also, I have confirmed that as of today there are:
22 cabins/lodging spots available for Friday July 13th, 2012
22 cabins/lodging spots available for Saturday July 14th, 2012
124 campsites available for Saturday July 13th, 2012
121 campsites available for Saturday July 14th, 2012
Mark that date: Wednesday March 28th, 2012. That’s the first day you can make your reservation. I would recommend booking on that date if possible.

The two of us are planning to be there. We live close to the park, so we will need no lodging. We are expecting guests from Nicaragua sometime in July, but because of the Visa situation, don’t have dates. We will let you know if our plans change. We love you guys and are thrilled to be invited!