First off, I've always liked Jim Harrison, he writes extremely interesting and literate books. His are the ones i keep the dictionary near to look up words like etiolated, adumbrate, and desuetude - the ones that don't look like anything I've ever read.
This book consists of two stories, The land of unlikeness, and The river swimmer.
Both are stories of coming to grips with your life, the changes that have come, and the changes to come, sadness and richness, and is there really an answer.
As usual he does a thoughtful job of making his characters believable and flawed, always trying to have their lives mean something. If you haven't read anything he's written, try one.