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 25.9 carats and measures 3cm X 1.75cm. It is not treated and backed. The price is $30 a carat or $$777. I have assigned a TG of 82 HG High Grade. Hidden Valley is very rare especially at the higher grades. I purchased this stone from Wayne Nelson who sold all of Hidden Valley in the late 1970’s.