You've gotten some good advice from the previous two fellows. Also, check out the Quality Deer Management website, they've got a density map that can be a lot of fun and a useful tool.

I'll second Speedgoat's general summary. West of the divide you'll find lower deer densities, but the potential for true monster bucks is higher. East of the divide, you can get into areas where you just can hardly believe how many deer you'll see. I once saw 13 whitetail bucks in the first 30 minutes of daylight on a heavily hunted BMA piece.

If you choose western MT, you're going for a true monster, with 140+ bucks being a real possibility, and 160+ bucks being theoretically possible (but don't count on it). You also may go home empty-handed. If you tackle the dark timber of western MT, thinkNORTHwest MT rather than SOUTHwest MT. Here in southwest MT, we have more human population than anywhere else, and thus our buck age structure generally doesn't match the rest of the state. (One exception is if you wish to bowhunt ONLY, and can get down onto the bow-only zone in the Bitterroot River bottom. In that area you can get into some monster bucks.) In northwest MT, you can get into areas with lots of 4 1/2, 5 1/2, and older bucks. Remember though, you won't see as many deer, and these deer aren't eating soybeans and corn, or even wheat and alfalfa. They're scraping out a living on forest browse, and they need 4-5 years to grow a good set of antlers. Bucks in the 3 1/2 year old age class in western MT will usually net score 105-120 B&C, rising to 125-150 at 4 1/2 y.o.

In eastern MT, when you zoom in on an area, it's important to call the local F&G guy as late as possible and check on the status of the deer herd. We get blue tongue epidemics that can knock a local herd down to where it's not worth hunting for a year or two. (I had this happen on a Region 7 hunt I was hot to go on in '03, blue tongue decimated the herd the summer before I was headed there to hunt. Since I really target 4 1/2 y.o. bucks, I've got to give that herd a few years yet to rebuild the older age classes.)

Regions 4-7 cover eastern MT, that's a lot of country. Get a DeLorme's gazette of MT, and get the BMA books, and start shopping like a little kid getting ready for Christmas. Most of your hunting will be on BMA lands, and you'll likely see lots of deer, whitetail and muley mixed.

In eastern MT, don't be so picky about waiting for the monster, because they are rarer there. The deal is this, lots of deer, few hunters, but not tons of cover either by whitetail standards. As a result, bucks seldom live past 3 1/2 years old here. (That's a mature buck by most standards, but hey this is MT.) Hunters let the 1 and 2 1/2 y.o.'s go pretty much, but they start blazing away at the 3 1/2 y.o.'s. Realistically, you should probably target a 3 1/2 y.o. buck, which will typically net score 110-125 in eastern MT.

On a good hunt, with say 3 guys, your northwestern MT hunt might go something like this: You see 1-3 bucks per full day in the woods, maybe one guy gets a 130+ buck, another gets a 110-class buck, and the third gets skunked.

Same hunt, eastern MT: you see 5-10 bucks per full day in the field, probably all three guys score, probably none of the three bucks scores more than 120, but they're all nice.

Obviously, your actual results will vary, but the relative comparison between eastern and western MT in valid. If you want to see lots of deer and do good, go to eastern MT. If you want to go for the homerun, and risk striking out in the process, go to northwest MT.