Since you're inviting us to "spend your money".... it really isn't too hard to make your own map which shows the boundaries of wildlife management areas, etc. The first step is to find the data, which should be available at your state's GIS website. Try some google searches - you are looking for
shapefiles, so something like "Montana WMA shapefiles" or similar queries will probably yield some hits. Alternately, start with the state's main website and look for the Geographic Survey, dept of natural resources, or similar agencies.
Once you have found the data it can be pretty simple, but here's where I'm going to spend your money. Buy a copy of Global Mapper:
http://globalmapper.com/ You can play with the free demo first to see what you think. It should be able to open any shapefiles you find (files with a .shp) extension. It can even open files inside a .zip (compressed) archive... it's really quite easy to use (but also incredibly powerful).
After opening the file, just export it as "polish format" .mp file. You could use cgpsmapper to compile the result into a Garmin-compatible map, but if you want something easier to use.... spend some more of your money on Mapwel:
http://www.mapwel.eu/ It can open the .mp file, display it on your computer where you can edit as desired, compile it as a map and even send it to your GPS.
