Hiero's Journey and
The Unforsaken Hiero, by Sterling Lanier, are both finally ebooks - Hiero's Journey back in April and the Unforsaken Hiero has a publication date of today (9/26). I've been waiting for a long time for these.
They're post-nuclear holocaust books, written in the 70s. Lots of weird mutated humans and animals. If you played the game Gamma World back in the day, I understand that Hiero's Journey was a big influence on that.