You can camp along the trail anywhere you can find to rough camp. There is a nice campground about 1/16 of mile pass the Cataldo trailhead about 28 miles down the trail from the Mullan trailhead which I would assum you would start if you where coming from Missoula Mt. Mullan is about 6 miles from the Idaho Montana border just off I-90, good place to start your ride. You can google the Trail of the Coeur d' Alenes and the friends of the trail of Coeur d' Alenes have a nice Website with more info!