When discussing Montana riding most folks think about Bear Tooth or Glacier. There's another great ride that's not so well known. It's got scenery, remoteness, twisties, and best of all NO TRAFFIC. It's a route out of Libby, MT that follows the Kootenai River and Lake Koocanusa and then circles back over the mountains to remote Yaak and then US Highway 2.
Starting in Libby take MT 37 north. At about 8 miles out of town you have to choose to go up the west or east side of Lake Koocanusa. The east side highway (MT 37) is busier and the road surface a bit better, but much less twisty. The west side road (USFS #228) has way less traffic, way more twisty, and I believe more scenic. Look at a map and you'll see how twisty this road is. The road surface is paved but there are a lot of black tar snakes and uneven in a few places. There's campgrounds on either side of the lake. The road rises above the lake always offering great views, is etched into the hillside in places, and follows the lake contour. We stopped along side the road and soaked in the view and knew we made the right choice being on the west side road - there was a lot of traffic that could be seen on the east side road, MT 37.
About 3/4's of the way up the lake a bridge over Lake Koocanusa connects USFS #228 and MT 37. From here you could go east on MT 37 to Eureka and US 95. Or, you could go north into Canada. If you stay on the west side of the lake the road now becomes USFS #92. USFS #92 (still paved) will take you up and over to Yaak, MT.
USFS #92 climbs steeply with a lot of twists and turns out of the Kootenai valley and over the mountains. The road climbs up until you are in sub alpine forests. Watch out for wildlife - deer, moose, and bear. This is a very remote and little traveled road. Make sure your bike is in good condition. There's no services or cell service until you get to Yaak. The road narrows in places to a single lane and there's no road lines or marking. Lots of blind corners and not many straight sections to pass. You might encounter some woody debris on the road. In some places bushes and small trees are encroaching the road. Generally the road surface is in good condition. The road twists and turns in semi open forest giving you lots of great views making it hard to focus to staying on the road. The road gently drops into deeper woods and more civilization when you reach Yaak. You can get food, groceries (limited), and fuel (no premium) at the Yaak store. The little bar/restaurant has good food. You can enjoy a cold one inside, on the deck, or outside on the grass by the river. There were quite a few other riders there. Lots of camping opportunities in and around Yaak.
From Yaak on the road is better, wider, and marked. Still some good curves but not as twisty. The road follows the Yaak River down to US Highway 2. There are some good stops - Yaak Falls - and fishing in the Yaak River. Again no services until you get to Bonners Ferry in Idaho.
If you fuel up in Libby you should have no problem making it to Yaak or as we did Bonners Ferry, iD. The route I describe is about 120 miles. From Lake Koocanusa to Yaak we never met any kind of vehicle going either direction and this was the middle of July. Going up Lake Koocanusa we maybe met about a dozen vehicles. Again it's a great scenic, remote, twisty ride making it a great motorcycle road. We did this ride on a pair of GS's (F800 & G650) but I wouldn't hesitate to ride it with my RT. For GS riding there are so many gravel side road opportunities.
If anyone wants the GPX route, or has other questions, PM me.
Alternatively there is a road in Yaak that will take you back to Libby that is paved but I have no knowledge of that road.