Your question is a bit difficult to assess without knowing the exact Ikenberry route. However, I was riding in the area last year. Started in Missoula and took the Trans Am to east of Big Hole Pass. Then took the Pioneer Mountains Scenic Byway to Wise River then MT 43 to Divide, then down to Melrose via the frontage road and then to Twin Bridges via Melrose Bench Road. From there I took MT 41 to MT 2 to Butte. From there, I took I-90 frontage roads and a little bit of the interstate (3 miles) to MT 1 and rode that all the way to Philipsburg and then eventually back to Missoula via MT 348/Rock Creek Rd., I-90 (again, about 3 miles) and local roads. Back in '00 I rode the Trans Am proper from Missoula to Twin Bridges and beyond.
No offense to the natives intended, but Butte ain't the nicest place in the world. There is only one camping option around--a KOA that looks and sounds (from the reviews I found) seedy. And it's right next to the interstate. However, the Finlen hotel/motel is a neat place. The motor lodge portion is relatively affordable and very retro. Despite its age, it was very well maintained, and the room was spotless. If you like larger cities, especially ones with interesting architecture and some history, Butte is worth a look. Just watch your bike. There are signs all around town about crime. A lot of it is meth-driven.
The ride from Twin Bridges to Butte was nice until hitting town. MT 41 to the junction with MT 55 is flat to gently rolling. There are some big rollers on 41 after that. You start up Pipestone Pass as soon as you turn onto MT 2. Pipestone seemed harder than it looked on paper. A narrow shoulder, but little traffic. We rode it July 5th, so that might not be the norm. Pretty ride. After Anaconda, MT 1 to Philipsburg is very nice. If you go this way, make sure to turn around as you descend. There is a cool waterfall that you will miss if you just look ahead. There is a great campground in Philipsburg run by a very nice woman. Rock Creek Rd. is fabulous. There is 30 miles of unpaved surface which was easily managed with 37c tires. Just before you reach I-90 there is a nice campground with a good restaurant (but no groceries around), or you can camp in the forest along the road, but there is no running water (other than the creek) and no services back there.
The original plan was to stay in Philipsburg, back track on MT 1 to MT 38, ride over Skalkaho Pass to Hamilton and then take the Trans Am back to Missoula. Unfortunately, Skalkaho Pass was washed out so we took the Rock Creek Rd. route which was recommended by an Adventure Cycling employee we fortuitously ran into at a hot springs resort in the Pioneer Mountains. If I could do it again, that’s what I would do.
I think the Trans Am is, overall, more scenic than the above-route via Butte is what you are looking for is mountain views. It’s certainly more difficult. There is free camping in Wisdom if you can tolerate the mosquitoes. The long slog north from there is very pretty and then there is a long descent all the way to Darby. Yummy sandwiches at the store in Sula. I highly recommend the Old Darby Alternative between Darby and Hamilton. There is a point where the mountains, sky and river seem to come together. Stunning. And the unpaved section is not bad.
If you are up for the challenge, doing the reverse of the above route to Twin Bridges is an option. It presents its own set of challenges, but the scenery is terrific. Send me a PM if you would like details or otherwise have any questions.
Here is a slideshow of the trip:http://www.youtube.com/watch?v=F7-k2ZMFL_I