The Hidden Valley of Oz

"The Hidden Valley of Oz" (1951) is the thirty-ninth of the Oz books created by L. Frank Baum and the only one written by Rachel R. Cosgrove. It was illustrated by Dirk Gringhuis.

Jam (Jonathan Andrew Manley), a boy from Ohio, builds a Collapsible Kite and attaches it to a crate and sets off to Oz with his two guinea pigs, Pinny and Gig, and a lab rat named Percy. Once in Oz, Jam realizes his pets can talk. He lands in the Hidden Valley, and becomes a prisoner, but they escape and set out on adventures with the Tin Woodman.

Cosgrove originally intended to have Jam travel to Oz by rocket, but the publishers informed her that that had already been done in "The Yellow Knight of Oz". Cosgrove's original opening was published posthumously in an issue of "Oz-story Magazine".

Cosgrove immediately set to work on a sequel, "The Wicked Witch of Oz", but Reilly & Lee turned her down on the grounds that the books were not selling. The next book admitted to the series was written by an author with two Newbery Awards, and not for more than a decade. "The Wicked Witch of Oz" was finally published in 1993 by The International Wizard of Oz Club. The club is currently the only publisher of the two Oz books, but neither book was assigned an ISBN.

oz books
before=The Shaggy Man of Oz
after=Merry Go Round in Oz
title=The Hidden Valley of Oz
year=1951