Nestled deep under 2,000 feet of solid granite in Colorado lies one of the most fascinating and mysterious military complexes in the United States: Cheyenne Mountain. Known broadly as a rugged command and control center, the mountain fortress hides a vast world beneath its surface—accessible only to those with the highest security clearances. Through a veil of secrecy and speculation, here are seven astonishing secrets about Cheyenne Mountain that reveal why it remains a cornerstone of U.S. national defense and mystery.

1. A Massive Fortress Beneath the Mountain

Cheyenne Mountain’s underground complex spans an incredible five acres of tunnels housing 15 connected buildings, ranging from two to three stories tall. Located about a mile inside the mountain entrance, employees must take buses to reach their offices. The buildings are ingeniously designed to withstand shocks—they rest on massive springs and are positioned at least 18 inches away from the surrounding rock to move independently in the event of blasts or earthquakes. The entire site is concealed behind enormous 25-ton blast doors, making it virtually impervious to outside attack.

2. Not Just NORAD – A Hub for Numerous Secret Agencies

While Cheyenne Mountain is often synonymous with NORAD (North American Aerospace Defense Command) and USNORTHCOM, these commands occupy only about one-third of the facility’s floor space and a mere 5% of its daily residents. The remaining two-thirds belong to other classified U.S. Defense Department agencies, whose identities and functions remain closely guarded secrets. Visitors report that many operational details are hidden, with equipment covered and photos restricted—fueling ongoing speculation about what other missions are conducted here.

3. An EMP-Proof Sanctuary

One of Cheyenne Mountain’s most vital features is its resilience to electromagnetic pulses (EMPs) caused by nuclear detonations. Thanks to the granite encasing the facility, it is virtually immune to EMP radiation, a crucial advantage since such pulses can disable electronics ranging from laptops and smartphones to cars and GPS systems. This protection ensures that the complex remains operational even following a nuclear strike, allowing it to serve as the primary backup command center for the United States.

4. Engineered to Withstand Explosions and Quakes

The complex boasts an expansive main tunnel more than two miles long, curving through the mountain, designed to minimize blast impacts. The tunnel angles avoid nearby gold mines but also reduce shockwave force on buildings and infrastructure. Remarkably, the facility’s electrical systems maintain 99.999% uptime accuracy because all wiring is installed with special angling to prevent damage from vibrations or aftershocks, ensuring critical functions remain uninterrupted even during seismic events.

5. A Self-Sufficient Bunker in Modern Times

Built originally for cold-war era nuclear threat scenarios, Cheyenne Mountain today continues to demonstrate extraordinary self-sufficiency. It has its own power plant, ventilation systems, water supply, hospital, grocery store, chapel, and even fitness centers. During the COVID-19 pandemic, the site adapted by isolating essential personnel inside, leveraging its design to function as a virus-safe bunker. Staff receive separate meals and use alternate entrances to maintain quarantine, showcasing how the fortress remains relevant in contemporary crises.

6. Behind the Scenes: Staff and Daily Life

Around 350 personnel work inside Cheyenne Mountain on a regular weekday, with the number dropping to roughly 130 during nights and weekends. Staff roles vary widely—it’s not only satellite and threat monitors but also includes security officers, medical personnel, maintenance workers, and more. Despite having no natural light or windows, employees enjoy amenities such as gyms (which can be converted to triage centers if necessary), chapels, and other comforts that sustain morale and readiness underground.

7. The Untold “Hangar 13” Mystery

Among the concrete facts lies the intriguing hint of an extra facility dubbed “Hangar 13.” While the complex officially has 15 interconnected buildings, speculation persists about hidden or undisclosed sectors—potentially reserved for specialized operations or experimental technologies. Though unconfirmed, this secretive reference adds another layer to the mountain’s aura, fueling rumors about activities yet unknown to the public.

The Enduring Enigma of Cheyenne Mountain

As much as Cheyenne Mountain has been depicted in popular media, from iconic images of a white rowboat on an underground lake to high-tech command rooms, much of what lies within remains classified. Its continued occupation by military and intelligence commands reflects its critical role in national defense, especially as new challenges like cyber warfare and space surveillance emerge. Protected by miles of granite and layers of secrecy, the mountain continues to be an unrivaled sentinel under the earth—an enigma that still fascinates and mystifies.

Whether as an EMP-proof haven, a secretive multipurpose military base, or a fortress designed for unimaginable crises, Cheyenne Mountain embodies the intersection of advanced engineering and national security in a way few places on Earth can match. Its subterranean depths are not just a marvel of construction but a testament to enduring vigilance in an uncertain world.