We come visit Montana a week or two each year and stay in the Helena area. We've hiked Mount Ascension and Mount Helena a few times, but what I really want to do is work my way up to Granite Peak. What are some good peaks to work on before jumping in there? Any input is greatly appreciated.
Climbing Granite requires endurance fitness, off trail route finding, and of course rock climbing and scrambling.
If you need to work on endurance fitness and route finding, then I suggest Tempest mountain. It will be very rewarding for you as the route is 90% the same. You can test your endurance by climbing it in a day, car to car with a small pack. Or you could load your overnight gear and camp out on Froze to Death like you were going for Granite. Aim for hiking from the car to the furthest camps below Tempest in a single day. Some people break this up into 2 days. But if you need to do that, it's a sign your endurance fitness could be improved. The benefit of Tempest is that you can chat with other climbers either on the trail or around camp to get their perspective without committing to the climb itself. And you really get a sense of accomplishment taking a step toward the real goal.
If you aren't sure about your rock climbing and scrambling ability, then try Mount Wood. There's nothing very exposed and you'll get the feel of what it's like to scramble up and down when you're tired out from the long approach. There is a great spot to camp just after crossing the inlet into Mystic Lake.
I hope this helps and good luck. Let us know if you have other questions.
I love the Tempest suggestion. Mount Wood is awesome in it's own right, and offers two distinct summits. The basin between Wood and Hague is a really cool, rarely visited place in the beartooths.
Another thing you could do to help get comfortable with exposure that is closer to Helena is Ross Peak in the Bridgers outside of Bozeman. Easy hike, a moment or two of gripping reality and a really rewarding summit. There is also a bit of routefinding. Electric Peak in Yellowstone is similarly challenging if you approach from Swan Lake Flats instead of the easier route from the north. This peak also offers the added bonus threat of grizzly bear encounters.