It's late in the season and winter is getting close. When this picture was taken the mainline to Alamosa had been abandoned and the Silverton branch was isolated. But it was still Rio Grande and the 470's still had the silly diamond stacks.
The DRGW narrow gauge was the last major steam operation in the U.S. The climb over 10,000 foot Cumbres pass was spectacular, with two engines handling 70 car trains. Hopefully these images convey some of the drama of mountain steam railroading.