This is a bit late, Dietrich passed away suddenly on December 15 and his memorial service was on January 23. I did, however, want to say something about him and acknowledge the kindness he showed to me and my students. Here's a picture of Dietrich in his beloved Widow Jane mine in Rosendale talking to my students about the 19th century Rosendale Cement industry.
Dietrich was only an acquaintance. Someone I'd chat with for a bit if I ran into him at a town meeting or a conference. Someone I'd call a couple of times a year to ask if I could bring a van load of geology students down to the Widow Jane mine (he always welcomed us). He was a kind, incredibly knowledgeable, and generous man.
What affected me the most about Dietrich's death was that the week he died I was working on a project having to do with the Rosendale Cement industry and I was thinking of calling him the following week to get together to discuss it. He knew more about this topic than anyone I know. Researching local history was a labor of love for him and a lot of local knowledge passed away when he did.
We always assume we have all the time in the world. We don't. Life is short.
An obituary is posted here if you'd like to read more about his interesting life.