The challenge is to complete the difficulty/terrain grid using only caches placed in Minnesota. That is correct, all 81 geocaches from 1/1 to 5/5 must be from Minnesota. I know it can be done because EskoClimber did it. While showing me how he uses GSAK to filter caches for different challenges that others have placed, he filtered everything but Minnesota from his finds and then ran the HTML_diffTerr.gsk macro which yielded this:

Here are the rules...
- All the geocaches must be in Minnesota
- The list must include a Traditional, Multi, Unknown, Virtual, Letterbox, and Earthcache.
Here is the FAQ
- Wherigo, Webcam, and Events (all types) are optional.
- NO CONTROL DATE
- This challenge cannot be used as one of the 81 to complete this challenge.
- The container is at the posted coordinates.
To show that you qualify submit any one of the following:
- Post your qualifying caches with the GC# and date found to your log
- Send me an email listing your qualifying caches with the GC# and date found
- Attach a bookmark list with your qualifying caches
- Screen shot from Project GC. Project-GC -->Tools-->Challenge Checkers-->Search for GC3H01E
This challenge has a 5-Star difficulty because of the requirements to fill the grid but the 4½-Star terrain is for the hide. I should warn you that EskoClimber helped me hide it. If you don't know him I'll explain. It is winter friendly. VERY winter friendly. He didn't take anything with him but then he is nuts. Pear Head can vouch for that. Park at the Mission Creek Boulevard Trailhead (N46° 41.550 W92° 16.433) or at the Munger Trail Bike Trail lot on 123 Ave W off the Becks Road.