He was Alex Honnold's co-author, right? I had no ideal- that's really sad.
Yes, David was a talented mountaineer until around age 40, exploring and making a number of tough first ascents in Alaska. Then he became more interested in backpacking with his wife Sharon, especially in the southwest U.S.
He has a mathematics degree from Harvard and a Ph.D. in English, and he spent a decade as a professor of English literature before moving to full time writing. Wikipedia says, "He is particularly noted for his books The Mountain of My Fear and Deborah: A Wilderness Narrative, chronicling major ascents in Alaska in the 1960s, which had a major impact on the form of mountaineering literature." (Both of these older books are on our shelves if you'd like to read them.)
In addition to writing his own books, he has co-authored books with Ed Viesturs, Jon Krakauer, Conrad Anker, Alex Honnold and more.
I happened to sit beside him at the Banff Book Festival a few years ago. He lives near Boston and I wondered whether he had any other mountain film/book festivals to recommend. He smiled, "There is nothing in the world like Banff." In his presentation this year, he commented that one of the biggest sorrows about his initial cancer diagnosis was that he had to cancel his trip to Banff with Alex Honnold to promote their book.
He was clearly exhausted after his presentation on Friday so I didn't line up to have my copy of his latest book signed. But he and Sharon attended a Saturday evening presentation, and I went up to talk to him briefly and express my appreciation for his body of work. It was a nice conversation with them both. He mentioned in his presentation that his throat cancer has metastasized twice and cannot be cured. He plans to keep working as long as he can.
He finished his presentation by reading the end of his latest book, Limits of the Known. He talked about his own mortality and finished with, "What I wish for, then, in that last conscious moment before the darkness closes in forever, is not the shining memory of some summit underfoot that I was the first to reach, not the gleam of yet another undiscovered land on the horizon, but the touch of Sharon's fingers as she clasps my hand in hers, unwilling to let go."