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Cheyenne Mountain is a location in Fallout Tactics, which can be reached from Bunker Epsilon.


During the 20th century, the American military created a facility underneath Cheyenne Mountain in the Rocky Mountains. Vault 0 is located here, housing the Calculator.

Vault 0

Main article: Vault 0

Vault 0 (Vault Zero), unlike most vaults involved in the vault experiments, was not an experiment in human behavior. It was constructed by expanding and reinforcing the Cheyenne Mountain Complex in Colorado and was by far the largest of the underground vaults (by volume). Many of the areas that comprise the massive interior layout of Vault 0 were originally designed to be the size of (and were often compared to) aircraft hangars, warehouses, and factories; these zones were for the construction of various machines that were ostensibly designed to serve the vault dwellers.

A massive amount of war robots and a cybernetic computer to control them (and serve as the vault's overseer) were placed here to ensure humanity's rebirth after the nuclear war. However, the Calculator becomes corrupted, drives the population of the vault to extinction, and initiates the pacification protocol, originally intended to kill all of the possible enemies to the people of Vault 0.

A massive army of robots emerges, producing more and more every day using several pre-War manufacturing centers such as Great Bend and Canyon City. The internal power supply of Vault 0 was not enough however and the Calculator had to use the nuclear reactors of Buena Vista to help power its growing robot war machine. Soon the Calculator became the main enemy of the Brotherhood of Steel. The Warrior, hero and general of the Brotherhood, led his squad to confront the Calculator, defeating the robots, which guards their main base. "Plutonius," a nuclear warhead from Kansas City, was placed on the nuke carrier, brought closer to the vault entrance and eventually blew up the entrance. The Warrior and his squad managed to survive the explosion thanks to a nearby fallout shelter (a small military bunker). Soon, the final battle begins.

Related missions

  • Cheyenne Mountain (mission): The mission at Cheyenne Mountain requires the player character to transport a nuclear warhead to the door of Vault 0 and then to get to safety in a bunker nearby.


Cheyenne Mountain appears only in Fallout Tactics.

Behind the scenes

The location was planned for inclusion in the cancelled Van Buren.