In addition, I'm continuing to narrow down areas I want to hunt. Here are some of the resources I've found to valuable for planning a trip that's 2000+ miles away.
The Montana wildlife department (FWP) distributes a booklet with maps of all the Block Management Areas (BMA's) and a description of each one. The BMA's are privately owned land that the landowners have decided to enroll for public use. This is what makes Western states such an awesome destination for hunters. That and the fact that states like Idaho are somewhere around 60% publicly-owned land, almost all of it open to hunters.
Also, Ben O. Williams has written some handy books for traveling bird hunters. The one I'm referring to here is called Wingshooting Wisdom: Prairie. It's a good resource.
Last but not least is the DeLorme Atlas and Gazeteer of Montana. Always helpful.