My Abandonment by Peter Rock

This book is based on the true story of a father and daughter who were discovered living in a cave in the woods in Portland, Oregon.  The story establishes their life together, which the girl really loves, and what happens once the authorities come in.  Clearly schizophrenic, the father gets increasingly paranoid as they evade authorities and try to reestablish the life they once had.  It's an interesting book with a fascinating finish that I think would be good independent reading for mature eighth graders, probably girls more so than guys.