the cache is not at the posted coordinates.
This is a bonus cache for the Grass Valley Mining adventure lab. the coordinates and hint will be revealed as you play the adventure lab and answer correct questions. You will need a smart phone and the app for Adventure Labs. then look for the Grass Valley Mining adventure lab. The Adventure Lab parking area is only open 10am - 4pm daily except for Thanksgiving, Christmas and New Years. The bonus is available all the time but will much easier to find in daylight hours.
Nearby is a Virtual the Worthy Steed, GCGX4P