I found an illustration from Songs of the Rockies, by Charles Edwin Hewes, 1915-1921 in the visitors center in Estes Park yesterday and sought out the book online. I was happy to find that you can read the book on Google books here. There are many beautiful drawings (block prints) by Dean Babcock are found throughout the book. I had trouble limiting myself, so I've posted a lot of the drawings:
I love this drawing of ptarmigans. I posted about these beautiful mountain birds in September.