Cheyenne Mountain Hides a Classified Bunker Behind 25-Ton Blast Doors

Cheyenne Mountain Complex (Colorado)

Workers began digging into Cheyenne Mountain near Colorado Springs on May 18, 1961. This became one of America’s most important Cold War military sites. The Army Corps of Engineers led this project when fear of Soviet nuclear attacks was high.

Engineers chose Cheyenne Mountain over Blodgett Peak because its granite had fewer weak spots.

Here’s how they built America’s most secure bunker. And while it’s off limits to the public, there’s a beautiful state park nearby where you can view this mammoth facility.

How 693,000 Tons of Granite Became a Military Base

Mining crews removed 693,000 tons of granite from Cheyenne Mountain between 1961 and 1964. They made the main tunnel curved, not straight, to redirect blast energy and avoid nearby gold mines.

In August 1962, workers found a dangerous crack in one ceiling. Engineers fixed this with a $2.7 million concrete dome. The digging created a 4.5-acre grid of chambers inside the mountain. All mining finished on May 1, 1964.

Buildings That Float on Springs

Inside the mountain stand 15 three-story buildings with a unique feature—they don’t touch the mountain. These buildings rest on more than 1,000 huge springs installed by Continental Consolidated Construction after winning the $6,969,000 contract on February 27, 1963.

Each 1,000-pound spring is made from 3-inch-diameter steel. This system keeps the buildings 18 inches away from the rock walls so they can move during earthquakes without damage. No building can shift more than one inch in any direction.

Protecting Against a 30-Megaton Nuclear Blast

The complex can survive a 30-megaton nuclear bomb exploding 1.2 miles away—2,000 times stronger than the Hiroshima bomb. Two 25-ton steel doors guard the entrance, sealing the facility within minutes of a warning.

The curved tunnel channels explosion energy outward instead of inward. Special valves in all outside connections close when sensors detect danger, protecting air, water, fuel, and sewer lines. Metal walls block electromagnetic pulses that would destroy electronics.

NORAD’s First Command Center

NORAD began on September 12, 1957, first working from Ent Air Force Base in Colorado Springs. This US-Canadian organization watches for threats to both countries.

General Earle E. Partridge suggested building the underground complex in 1956. The Air Force completed the Combat Operations Center and gave it to NORAD on January 1, 1966. NORAD moved from Ent to Cheyenne Mountain on April 20, and by July 1, 1966, the center was fully operational.

Computers That Watched the Skies

The $5 million Delta I computer system started working on October 28, 1966. It tracked objects orbiting Earth and identified space threats.

Workers had installed the first Philco 212 Computer on May 7, 1965, while construction continued. Burroughs Corporation built the control system connecting radar sites across North America. The system processed data in one-millionth of a second—vital when minutes determined survival during the Cold War.

The Space Defense Center Moves In

The Space Defense Center moved from Ent Air Force Base to Cheyenne Mountain on September 3, 1965, before construction finished. The 1st Aerospace Control Squadron, which tracked space objects, followed in April 1966.

The center settled next to the NORAD command center on February 6, 1967. This location improved coordination between air defense and space monitoring. The center combined data from the Air Force’s Space Track and Navy’s Spasur systems, creating a complete picture of everything in orbit.

Self-Sufficient Underground City

The complex works like an independent city with its own power plant containing six diesel generators. Four water reservoirs hold 1.8 million gallons of drinking water and 5.3 million gallons for industrial use. Natural springs inside the mountain provide more water than needed.

The underground base includes a medical clinic, store, cafeteria, and gym. Two small boats remain stored inside for crews to inspect water systems and rock walls.

Presidential Visit During Construction

President John F. Kennedy visited NORAD’s temporary headquarters on June 5, 1963. Military leaders briefed him about the Cheyenne Mountain project during a critical construction phase.

Kennedy made this visit after attending the United States Air Force Academy graduation nearby. The chair Kennedy sat in during this meeting is now displayed at the Peterson Air and Space Museum.

Communications Network Built to Survive

In 1965, engineers created a special communications system for nuclear war scenarios. Bell Laboratories developed the “Close-in Automatic Route Restoral System,” running through deep tunnels for protection.

Communication nodes placed 30 to 120 miles from the complex created multiple paths that would automatically reroute if any section failed. This network connected radar stations across North America, the UK, and Greenland. The NORAD Warning System became operational on May 20, 1966.

The Final Piece – Civil Defense Integration

The National Civil Defense Warning Center opened inside the bunker on January 4, 1967. This center could alert civilians about attacks through emergency broadcasts.

The Space and Missile Systems Organization activated its operations center on July 1, 1967. Total construction cost reached $142.4 million (about $1 billion today). The entire complex became fully operational on February 6, 1967, completing America’s most advanced defense command center.

The Cheyenne Mountain Complex Today

Cheyenne Mountain Complex is located at 1 NORAD Road in Colorado Springs, Colorado. The military facility does not offer public tours due to security and operational requirements. This policy has been in place since the September 11, 2001 attacks and continues as of 2025.

You can see the mountain’s exterior from several public locations.

Cheyenne Mountain State Park on Highway 115 offers hiking trails with mountain views. Admission costs $10 per vehicle for daily access.

The nearby Cheyenne Mountain Zoo at 4250 Cheyenne Mountain Zoo Road provides another vantage point.

For those interested in military history, the Peterson Space Force Base Museum (150 East Ent Avenue) features NORAD and Cheyenne Mountain exhibits, including artifacts from the facility.

The museum is free and open Tuesday through Saturday, 9:00 AM to 4:00 PM.

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