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 10.5 carats and measures 2.75cm X 1cm. It is priced at $10 a carat or $105. It is not treated and backed. I have assigned a TG of 74 MG  Mid Grade. I purchased this stone from Wayne Nelson.