Forbidden Zone Geocaches
  FBZ Missions  
  · Stone of the Lost Valley
· The Bunkers
· Mission Gorge
· Rock River Burial Mound
· Supernatural Supernova
· Little Green Men
· The Forbidden Zone
· The Monkey's Triangle
· Warlock Mine



Don't have an account yet? You can create one. As a registered user you have advantages such as the ability to display and track your Operation Silverback progress, earn points, upload images, and post comments in the forum.

  Silverback Cipher  
Silverback hunters should be familiar with the “pigpen” or masonic cipher, which is a simple substitution cipher exchanging letters for symbols based on a grid.

This cipher can be used to decrypt directions and secret codewords at FBZ geocaches!

  External Links  
  · 1: The FBI Vault
· 2: Project Blue Book
· 3: Aliens the Truth
· 4: The CIA Vault

 << SGTF Special Operations
Geocaching Reference Number TB3VY4F

Worth 60 Points (Create an account to enter TB tracking number and earn points!)

POTAM TOL 09 Tracking Bug Image

Current GOAL:
Operatives can discover this intelligence (codename POTAM TOL 09) as part of the final classified Operation Silverback mission.

Its discovery is worth 60 points on this Web site!

About This Item:
Its true whereabouts are unknown, but most suspect this TOP SECRET project coin is maintained in an undisclosed location in the mountains of Southern California.

Operatives who have logged this TB...

  • Lieutenant Colonel BALCANTHEZ
  •  (Sun 25 Mar 2012 @ 11:55:37 BST; 1332672937 seconds since Unix Epoch (POSIX) 01 Jan 1970 00:00:00 UTC)
  • General OESTEADO
  •  (Sun 09 Apr 2017 @ 13:58:11 BST; 1491742691 seconds since Unix Epoch (POSIX) 01 Jan 1970 00:00:00 UTC)
  • Honorable Discharge FLAGMAN
  •  (Thu 01 Jun 2023 @ 20:47:46 BST; 1685648866 seconds since Unix Epoch (POSIX) 01 Jan 1970 00:00:00 UTC)
  • Green Beret STANSD
  •  (Wed 28 Jun 2023 @ 13:03:01 BST; 1687953781 seconds since Unix Epoch (POSIX) 01 Jan 1970 00:00:00 UTC)

   Operation Silverback Prize Ring SILVERBACK Prize Rings

Those who create an account on and enter mission codewords and POTAM tracking bug numbers receive points towards an Operative ranking. Operatives who achieve the rank of General (700 points) are eligible to receive an official silver Operation Silverback trackable ring from Oakcoins. Gold rings are available for those who reach the rank of Green Beret (or higher).