So sorry to hear this.
When I first started FF, I read an article of his that he had written for fly fisherman magazine, called "The little juniata - an improving river with diverse hatches". And decided to give it a try. It quickly became my favorite stream - and still is, almost 40 years later.
I also bought his book "Meeting and Fishing the Hatches", which was my first FF book.
And through his writings, he kinda became my fishing guru. Many of the streams I now fish, were first tried because of what he wrote about them. And I just about always found what he said about the waters to be true.
I was fortunate to be able to meet and fish with him several times. And even traded some flies with him.
Fond memories that I'll cherish for the rest of my life