Motherlines by Suzy McKee Charnas
Oh, I don't even know what to say about this one. It won a retrospective Tiptree Award. It's about a world where men hold "fems" in slavery. One of them escapes (apparently I read book 2 first by mistake) and this book starts off with her realizing that she doesn't really have anywhere to go.
Luckily for her, there are still women who live outside of the men's control. In fact, there are two societies that interact throughout the book: the escaped fems and the women. The women have been genetically modified so that they can reproduce without men: essentially by cloning themselves. Which involves them having sex with their horses. I must say, I wasn't expecting that, although it was tastefully done as these things go.
I still can't quite decide how I feel about this book. Many of the characters irritated me, but I think that was intentional on the part of the author. The societies were well done. Perhaps if I'd read the books in proper order I'd have appreciated this one more. I plan to give it a go. The 3rd book in the series also one an award, so we'll see.