A word of caution, at least for Google bike routes, is that it does not distinguish between paved and non paved roads so if you want paved roads be careful. Sometimes you can use the satellite view to tell if it is paved or not.
Case in point: If you ask Google for a bike route between Twin Bridges, MT and Wisdom, MT, which are both on ACA's Trans Am, the first suggested route (which is also the shortest) sends you on a 20 mile unpaved road between Twin Bridges and Melrose that is rough in places, especially the part where you climb. It's not available on Street View so you have to rely on the satelite image. That image is not definitive. Could be unpaved but also could be light colored paving. Compounding the problem is the fact that Google draws a line on the road even in the satelite image mode. The I-15 through Melrose has an orange tint similar to the organe used in the map image mode.
The second suggested route is the one the Trans Am follows.