Atlas F Site 577-9 Missile Silo, Hollis Oklahoma

Atlas F Site 577-9 was one of the twelve SM-65F Atlas intercontinental ballistic missile launch complexes assigned to the 577th Strategic Missile Squadron at Altus Air Force Base, Oklahoma. The site was the squadron's Site 9 and was located near Hollis in Harmon County, Oklahoma.

The site belonged to the 11th Bombardment Wing, which was redesignated the 11th Strategic Aerospace Wing on 1962-04-01, and to the 577th Strategic Missile Squadron, the Atlas F missile unit assigned to Altus AFB. Because Atlas F launch complexes were self-contained vertical-silo sites with launch-control functions at the complex itself, rather than Minuteman-style unmanned launch facilities controlled from a separate remote launch control center.

Site 577-9 is inactive and decommissioned as a military missile installation. Construction at the site began on 1960-06-21, the site was turned over to the Air Force on 1961-10-25, and the Altus Atlas F missile force became operational in October 1962. The site remained part of the operational 577th Strategic Missile Squadron until the Atlas F weapon system was removed from service in 1965. Site 577-9 was decommissioned on 1965-03-25, the same date on which the 577th Strategic Missile Squadron was inactivated.

Its assigned operational missile was General Dynamics Atlas missile 51F, serial number 61-2537, Air Force tail number 537. The missile was accepted on 1962-02-28 and delivered on 1962-03-19. Unlike some former Atlas missiles that later flew as research, reentry-vehicle, or space-launch boosters, the Site 577-9 missile is listed as not launched and salvaged as scrap.

The former missile property later entered the Formerly Used Defense Sites environmental record as ATLAS MISSILE NO. 9 / K06OK0409. The 2015 U.S. Army Corps of Engineers FUDS inventory lists the property at Hollis, Harmon County, Oklahoma, with Building Demolition / Debris Removal and Hazardous, Toxic, and Radioactive Waste project categories. ProPublica's DERP-based summary lists ATLAS MISSILE NO. 9 at Hollis, Harmon County, as Response Complete. The site should be treated as a decommissioned former missile complex on non-public property with no public access.

Location, Landscape, and Site Description

Site 577-9 is in rural southwestern Oklahoma near Hollis, west of Altus Air Force Base and close to the Oklahoma-Texas border. The surrounding landscape is open plains and agricultural country, the same broad setting that made the Altus missile field suitable for dispersed single-missile launch complexes. The location gave Strategic Air Command a launch point far enough from Altus AFB to avoid concentrating the entire squadron at the parent base, but still close enough for wing, squadron, maintenance, security, communications, engineering, and logistics support.

The site's location in Harmon County also reflects the way the Altus missile field crossed county and state lines. USAF unit-history material explains that the twelve Altus Atlas F launcher locations were distributed around the region at or near Lone Wolf, Hobart, Snyder, Cache, Manitou, Frederick, Creta, Hollis, Russell, Willow, and Fargo, Texas. That network required land acquisition across several counties and turned scattered farm and ranch parcels into hardened missile complexes.

Site 577-9 was not a surface launch pad. It was an Atlas F vertical-silo launch complex built around a deep, reinforced-concrete underground silo, an elevator launcher, heavy silo doors, an underground launch-control and equipment area, utility rooms, electrical and environmental-control systems, communications equipment, propellant and liquid-oxygen handling systems, security fencing, surface support features, and access roads. The missile stood vertically inside the underground silo. During a launch sequence, it would be raised to the surface and launched from above ground, rather than fired from within the closed silo.

Site 9 satellite images show a recognizable former Atlas F compound. The image evidence shows a fenced or formerly fenced launch area with the surface trace of the silo-door area and associated support features.

Strategic and Cold War Context

Site 577-9 existed because the United States was rapidly building a survivable land-based nuclear deterrent during the early 1960s. Atlas was the first operational U.S. intercontinental ballistic missile, and the National Park Service describes Atlas as the Air Force's first operational ICBM. The Atlas program began as a first-generation crash effort to place long-range ballistic missiles on alert before later, more maintainable systems such as Titan II and Minuteman could fully mature.

Atlas F was the most protected operational version of the Atlas missile. The earlier Atlas D and Atlas E systems used surface, gantry, or horizontal coffin-launcher arrangements. The F model was placed upright inside an underground silo. That design provided more protection from weather and attack, gave each missile its own hardened launch complex, and reduced the vulnerability that came with older aboveground configurations.

The system was powerful but transitional. Atlas F was liquid-fueled. Its RP-1 fuel could be kept on board the missile while on alert, but liquid oxygen oxidizer had to be loaded during the countdown. The missile also required continual pressure management because the Atlas airframe depended on internal pressure for structural rigidity. The site therefore represented both a major advance in survivability and a maintenance-intensive stage in ICBM development. Later solid-fueled Minuteman sites would be simpler, faster to maintain on alert, and capable of launch from underground silos without the same liquid-oxygen servicing process.

Site 577-9 entered the operational force at an especially tense moment. Official Altus AFB chronology states that the 577th Missile Squadron activated on 1961-06-01 to operate twelve Atlas F missile sites within a forty-mile radius of Altus and that the squadron became operational on 1962-10-10. USAF unit-history material lists SAC turnover and operational status on 1962-10-09. The one-day difference is a source conflict between two public Air Force-derived summaries, but both place the Altus Atlas F force on operational status immediately before the Cuban Missile Crisis. During that crisis, the 577th SMS sites were part of Strategic Air Command's nuclear alert posture.

Construction and Activation

Construction of the Altus Atlas F missile field began as part of the nationwide program to deploy hardened ICBM launchers at dispersed inland sites. Official Altus AFB chronology states that construction began on the first of the twelve Atlas F missile sites around Altus on 1960-05-01. USAF unit-history material records that the Corps of Engineers, Tulsa District awarded the basic construction contract for the Altus Atlas F field to Morrison-Knudsen and Hardeman and Associates, with a combined bid of just over $20.9 million.

The same USAF unit-history material records that the twelve launcher locations were sited around the region and that land acquisition required the Tulsa District's Real Estate Division to file condemnation suits against 477 landowners in six counties to acquire 12,879 acres. That information is important to understanding Site 577-9 because the Hollis site was not an isolated construction job; it was one parcel in a large, synchronized missile-field construction program.

Construction at the Hollis site began on 1960-06-21. The work required excavation of the deep silo, placement of heavily reinforced concrete, installation of the elevator-launcher and silo doors, construction of the underground control and support areas, and installation of liquid-oxygen, RP-1, power, communications, ventilation, security, and environmental-control systems.

The site was turned over to the Air Force on 1961-10-25. Turnover did not mean the launch complex instantly became part of a certified operational force. First-generation ICBM activation required overlapping stages of construction completion, equipment checkout, missile delivery, site acceptance, crew training, propellant-system testing, communications integration, and SAC operational certification. The Altus Atlas F force reached operational status in October 1962, immediately before the Cuban Missile Crisis.

Missile System and Technical Role

Site 577-9 was built for the SM-65F Atlas, the final operational Atlas ICBM variant. The Atlas F was stored vertically underground and raised to the surface before launch. The silo gave the missile protection while it was on alert, but the missile was not a cold-launched or hot-launched weapon fired from the closed silo. Its launch method still required the complex operation of opening heavy doors, raising the missile on an elevator, completing propellant procedures, and launching from the surface.

The Atlas missile used a stage-and-a-half propulsion arrangement. Its booster engines and sustainer engine were all ignited at launch, with the booster section later dropped while the sustainer continued to burn. Atlas F used liquid oxygen and RP-1. Because liquid oxygen could not be stored indefinitely in the missile, the countdown process required oxidizer loading before launch. That made propellant-loading systems, liquid-oxygen handling, ground support equipment, and trained crews central to every Atlas F site's operational role.

Public museum and historical sources describe the Atlas F as a fast-reacting first-generation ICBM by the standards of its time. The National Park Service states that Atlas F was held in a blast-proof silo-lift configuration and could be launched in approximately ten minutes. F.E. Warren AFB's Atlas fact sheet explains that the silo was for protection and that an elevator raised the missile to ground level for launching. These descriptions match the Site 577-9 configuration.

The National Air and Space Museum identifies the Mark 4 reentry vehicle as the RV used on U.S. Air Force Titan I and Atlas E/F ICBMs in the early 1960s, carrying a W-38 nuclear warhead with a yield of about 3.75 megatons.

Operational History

Site 577-9's active missile career was brief but strategically important. The 577th Strategic Missile Squadron was activated for missile duty on 1960-12-12 and organized at Altus AFB on 1961-06-01. It was assigned to the 11th Bombardment Wing, later the 11th Strategic Aerospace Wing. The squadron's weapon system was the SM-65F Atlas from 1961 to 1965.

The Hollis launch complex became part of a twelve-site operational missile field. Unlike a later Minuteman launch facility, each Atlas F complex was an involved site in its own right. It contained the missile, the silo, launch-support systems, and launch-control facilities at the complex. Crews, maintenance technicians, security personnel, propellant specialists, communications technicians, and support teams from Altus AFB and the missile squadron kept the site integrated into Strategic Air Command's alert system.

Operational duty at Site 577-9 would have centered on maintaining the missile and launch complex in a safe and ready alert condition. The Atlas airframe required pressure management. The RP-1 fuel and liquid-oxygen systems required careful inspection and servicing. Electrical power, communications, access controls, environmental systems, hydraulic and elevator mechanisms, silo doors, and safety systems all had to be maintained. Atlas F was not a simple unattended tube in the ground. It was a complicated first-generation launch complex that depended on frequent technical attention.

The assigned missile, Atlas 51F / tail number 537, was accepted on 1962-02-28 and delivered on 1962-03-19. The site was already turned over to the Air Force by that point, but the full squadron did not enter operational status until October. USAF unit-history material records that the first Series F Atlas at the 577th SMS was placed on alert early in August 1962 and that all twelve missiles were put on alert status during the Cuban Missile Crisis. Site 577-9 therefore belonged to a missile force that entered its most demanding Cold War alert period almost as soon as it became operational.

Deactivation and Disposal

The Atlas F weapon system had a short service life. By late 1964, the Department of Defense had decided to accelerate the retirement of remaining Atlas D, Atlas E, Atlas F, and Titan I systems. SAC chronology entries for late 1964 and early 1965 record the progressive removal of Atlas missiles from alert and the inactivation of Atlas squadrons. USAF unit-history material records the 577th SMS phaseout sequence: the first 577th SMS ICBM was removed from alert on 1964-12-30, the last was removed from alert on 1965-02-04, and the last was shipped on 1965-02-10.

After deactivation, Site 577-9 left active military service and eventually entered environmental tracking as a Formerly Used Defense Site. The 2015 U.S. Army Corps of Engineers FUDS inventory lists HOLLIS, ATLAS MISSILE NO. 9, K06OK0409, with two project entries: Site 01 for Building Demolition / Debris Removal and Site 02 for Hazardous, Toxic, and Radioactive Waste. A GAO-published FUDS status table identifies ATLAS MISSILE NO. 9 / K06OK0409 in Harmon County and lists a High-risk HTRW entry with long-term management, as well as a BD/DR entry. ProPublica's DERP-based summary later lists ATLAS MISSILE NO. 9 at Hollis, Harmon County, as Response Complete.

Current Status and Site Use

Site 577-9 is a decommissioned former Atlas F launch complex in Harmon County, Oklahoma. It is not an active military installation. No public museum, interpretive program, or authorized visitor program was found for the site. The current individual parcel owner was not verified, but the site should be treated as private or otherwise non-public property.

Satellite imagery indicate that visible former launch-complex features remain at or near the coordinate, including the surface footprint of the launch area and associated former Atlas F structures or pads.

Chronology

• 1960-01 Public announcements identified Altus AFB as the future hub for twelve Atlas F missile sites in southwestern Oklahoma and nearby Texas.
• 1960-05-01 Official Altus AFB chronology states that construction began on the first of twelve Atlas F missile sites around Altus AFB.
• 1960-06-21 Construction began at Atlas F Site 577-9 near Hollis, Oklahoma.
• 1961-06-01 The 577th Missile Squadron activated at Altus AFB to operate twelve Atlas F launch sites.
• 1961-10-25 Site 577-9 was turned over to the Air Force.
• 1962-02-28 Atlas missile 51F / serial number 61-2537 / tail number 537 was accepted.
• 1962-03-19 Atlas missile 51F was delivered for the Altus operational ICBM mission.
• 1962-04-01 The 11th Bombardment Wing was redesignated the 11th Strategic Aerospace Wing.
• 1962-08 USAF unit-history material records the first Series F Atlas ICBM at the 577th SMS placed on alert early in the month.
• 1962-10-09 USAF unit-history material lists SAC turnover and operational status for the 577th SMS missile force.
• 1962-10-10 Official Altus AFB chronology states that the Atlas F missile silos became operational.
• 1962-10 The 577th SMS Atlas F sites were on heightened alert during the Cuban Missile Crisis.
• 1964-05-14 A propellant-loading explosion destroyed squadron Site 577-6 near Frederick, Oklahoma; this did not occur at Site 577-9.
• 1964-11-19 Secretary of Defense Robert S. McNamara announced the planned phaseout of Atlas D, Atlas E, Atlas F, and Titan I missiles by the end of June 1965.
• 1964-12-30 USAF unit-history material records the first 577th SMS ICBM removed from alert.
• 1965-02-04 USAF unit-history material records the last 577th SMS ICBM removed from alert.
• 1965-02-10 USAF unit-history material records the last 577th SMS ICBM shipped.
• 1965-03-25 Site 577-9 was decommissioned and the 577th Strategic Missile Squadron was inactivated.
• 2015-09-30 The USACE FUDS Oklahoma inventory listed HOLLIS, ATLAS MISSILE NO. 9, K06OK0409, with BD/DR and HTRW entries.
• 2017 ProPublica's DERP-based Bombs in Your Backyard dataset listed ATLAS MISSILE NO. 9, Hollis, Harmon County, Oklahoma, as Response Complete.

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