The first edition of Rocky Mountains has the letter A on page 160. © Copyright 1964 Golden Press, Inc. Published by Golden Press, Inc., New York, N.Y. Cover price is $1.00. The number on the spine is 24406. Listed as a Golden Regional Guide. (image #1)
The only cover (text) change to Rocky Mountains is shown next. Still dated 1964 with a $1.95 cover price. The back cover also changed. Four of the ten illustrations have been deleted. My copy has the letters HIJ on page 160. No longer called a Golden Regional Guide on the cover.
Image #1 also exists in a large (5 ¼ by 7 ¾ inch) hardcover. The number on the back cover is 63525.
No revised edition exists. Out of print.