Industrial mineral site no. 1782, known as "Double Hill Deposit #3" is a site in San Juan County, Washington. This site has been associated with limestone and marble. A notation found in DGER Bulletin 52 on page 154-155 says "The limestone is light gray in color and dense to finely crystalline in texture", and designates the value as "The limestone is of good quality except for the siliceous impurities".