Trying to ID this scifi/fantasy book

A question in GQ sparked a memory and I went looking for a book on my shelves that I cannot find.

My memory has it entitled The Man In The Tree. But I can’t spot it on Amazon with Man/Tree search combinations.

Originally I thought the author was Gene Wolfe, but now that I’ve thought about it I’m pretty sure that the protagonist was named Gene and I have no idea who the author was.

The premise is that at each moment when two *different *things can happen, the universe splits off and *both *things happen, one in each universe - thereby creating an infinity of universes.

The protagonist is a giant of a man (literally) who can reach into the other universes and make the things that happened there, happen here.

Anyone know the book?

It looks like this might be it.

Same title as you remembered, and if you scroll down to the reviews, there’s one that mentions the protagonist being called “Gene”.

Thank you. That is indeed it. I wonder why I couldn’t find it… I typed The man In the tree into their search engine more than once and it just would not come up.

But that is it, thanks.