Durango to Silverton Rail Durango to Silverton narrow gauge tracks are visble along 550. Southbound travelers first see tracks near mile marker 33. Part of this Highway Travel Guide Is called 'San Juan Skyway', a National Scenic Byway. Highway 550 - Durango to Montrose Part of the San Juan Skyway. Running northward through the San Juan Mountains to Montrose, this beautiful historic drive is alive with fantastic scenery and possibilities for hiking, biking, jeeping and exploring amongst the played out gold and silver mines of the gold and silver rush of the late 1800s.