"On its "Rockies to the Red Rocks" route, Canadian luxury train operator Rocky Mountaineer takes passengers between Denver's Union Station and the heart of downtown Moab, Utah. The voyage also features an overnight stop in Glenwood Springs, Colorado. The trains only travel during the day, so you'll never miss a moment of the ever-changing landscapes through their enormous, perfect-for-leaf-peeping windows. The route runs from April to October, with mid-September to early October being prime time for fall foliage viewing. Highlights of this Rocky Mountaineer itinerary include crossing the Continental Divide and passing through environments that range from lush mountain valleys to vast, open canyons." - Travel + Leisure Editors