If it's truely an "eastern Colo." hunt, meaning on the eastern plains of Colo., then chances are that it'll be dry and cool, maybe even cold. Terrain is flat, and there aren't any bears, or at least not enough to even concider them in planning. Rarely would a GPS be needed any where in eastern Colo. either, again for the most part, it's open terrain and not many hills.
Not many elk live on the eastern side, but there are pockets on private land.