Rocky Mountain stream flies were more to the adams, cahill, green drake, & wulffs instead of the Catskill style dry flies; along with the usuals. The caddis wasn't even elk hair at the time ( deer hair ) & there are alot of basic nymphs because that's what got fished most . The thought of cutting the tail off of a $1.00 fly to make a caddis to catch fish was a big decision back in those days ! What if you cut the tail off the wrong dry fly & caught no trout ?