Rachel Cosgrove was born in 1922 in Maryland into a family of book lovers. Among the many books they read were the Oz books, and so despite working as a pharmacologist, it only seemed natural to her to write an Oz book for her own and her mother's enjoyment.
On a whim she sent a copy of the manuscript to Reilly and Lee, and although they weren't adding any new books to the series at the time, they gave her encouragement and comments. She made a few changes, then Reilly and Lee asked if they could publish it after all.
The Hidden Valley of Oz, published in 1951, was Rachel Cosgrove's first published book, but far from her last, as she continued to write mysteries, romances, juveniles, and science-fiction.
After marrying Norman Payes in 1954, her books were published under several variations of the name Rachel Cosgrove Payes, with some of her sci-fi published under the name E. L. Arch, an anagram of her first name.
Rachel Cosgrove Payes died in 1998.
Pseudonym/s: Rachel Cosgrove, Joanne Kaye