Hi,
I always thought that the train shootout scene at the end was filmed at Old Tuscon. I tried to look this up and found the following shooting locations.
I do not recall the D&RGW scene(s).
Doug vV
Filming locations for
How the West Was Won (1962)
Alabama Hills, Lone Pine, California, USA
(attack by Indians)
Badlands National Park, Interior, South Dakota, USA
Battery Rock, Shawnee National Forest, Illinois, USA
Bent's Old Fort National Monument - 35110 Highway 194 East, La Junta, Colorado, USA
Black Hills, South Dakota, USA
Cave-In-Rock State Park - 1 New State Park Road, Cave-In-Rock, Illinois, USA
Cedar Mountain, Utah, USA
Corriganville, Ray Corrigan Ranch, Simi Valley, California, USA
Custer State Park - 13329 U.S. Highway 16A, Custer, South Dakota, USA
Denver & Rio Grande Western Railroad, Durango, Colorado, USA
Duck Creek Village, Duck Creek, Kanab, Utah, USA
High Sierra Mountains, California, USA
Inyo National Forest - 351 Pacu Lane, Bishop, California, USA
Lone Pine Campground, Lone Pine, California, USA
(homestead)
Monument Valley, Utah, USA
Oatman, Arizona, USA
Paducah, Kentucky, USA
Superior, Arizona, USA
Tonto National Forest - 2324 East McDowell Road, Phoenix, Arizona, USA
Tucson, Arizona, USA
Uncompahgre National Forest - 2250 Highway 50, Delta, Colorado, USA
Verde River railroad bridge, Perkinsville, Arizona, USA
Whitney Portal Road, Lone Pine Creek Canyon, Lone Pine, California, USA