Hello! I am a local to that area (Butte), and Outdoor Fool is correct. The Anaconda Pinter Wilderness and the Flint Creek Range. Both Anaconda and Phillipsburg are very cute little towns separated by Georgetown Lake. Maybe an Airbnb on the lake? There are also campgrounds there. You’ll have everything you need in Anaconda or Phillipsburg, restaurants and breweries, and the small town feel. There are a couple forest service cabins around that area (check recreation.gov).
A very easy yet absolutely stunning day hike that would be good for your friend would be Storm Lake to Goat Flat, right outside Anaconda. The views are practically on par with Glacier, and it’s only a couple miles hike. The hike could be extended to other wilderness lakes the trail leads to. Pick up a map of the Anaconda Pinter wilderness and check it out!
Another easy yet awesome introduction to the Pintlers is a 10mile loop by Warren Peak and the Carpp Lakes up Maloney Basin! You’ll enter the wilderness via one of the “Portals” they call the access points. In late June or early July the wildflowers are insane.
And yes, taking a drive from this area over Skalkaho Pass to the Bitterroot Range (Hamilton) is also a good option!
That’s just a start, you can ask me anything else if needed. Have a great time planning your trip!