Found: Young adult - time travel neanderthals

This was a book about a young girl who runs away and falls asleep under a rock overhang in a park. When she wakes up she is in the times of the neanderthals(?) or at least pre-historic. She lives with them a while, goes through puberty and then is returned to her time.

Read it in the 70's or early 80s.

thanks,

Saturday, the Twelfth of October by Norma Fox Mazer.

Thank you!! That's it!

How do I edit the title to Found?!?!?