Hidden Valley is a little known mine. The story is told in Turquoise in America Part Two 1910-1990 and Part Three The Stories of Turquoise 1990-2020.
 
This cab weighs 14.8 carats and measures 2.5cm X 1.5cm. It is priced at $12 a carat or $177. It is not treated and backed. I have assigned a TG of 77 HMG  High Mid Grade. I purchased this stone from Wayne Nelson.