Atlas F Site 551-1 Missile Silo, Elmwood Nebraska

Long after Atlas F Site 551-1 stopped holding a nuclear missile on alert beneath the Nebraska countryside, the ground still told the story: a hardened Cold War silo turned private salvage-yard property, tied to a documented FUDS cleanup record and groundwater bioremediation work. This was not just one more dot in the Lincoln missile field. It was one of the buried launch complexes where the Air Force tried to make America's first generation of silo-based ICBMs survivable, fast-reacting, and dispersed enough to complicate any Soviet first strike.

Atlas F Site 551-1 was one of the twelve Atlas F intercontinental ballistic missile launch complexes assigned to the 551st Strategic Missile Squadron at Lincoln Air Force Base, Nebraska. The site stood southeast of Elmwood in Cass County. In official and semiofficial records it appears under several related identifiers: Atlas F Site 551-1, Air Force Operational Site Number 1, GSA Acquisition Site ID 10, Corps of Engineers Construction Site Number 10, and Former Lincoln Air Force Base Atlas "F" Missile Site 1. Its assigned operational missile was General Dynamics manufacturing number 34F, General Dynamics serial number 60-5557, Air Force missile tail number 557.

The site was built for the SM-65F Atlas, the final operational version of the Atlas ICBM. It was a first-generation, liquid-fueled missile housed in a hardened vertical silo-lift launch complex. The parent base was Lincoln AFB; the assigned operational wing was the 98th Strategic Aerospace Wing; and the operating missile unit was the 551st Strategic Missile Squadron. Atlas F sites did not use the later Minuteman-style arrangement of unmanned Launch Facilities controlled from remote Launch Control Centers. Each Atlas F complex included its own underground launch-control space connected to the silo and was manned during alert operations.

Site 551-1 is no longer an active missile installation. It was decommissioned in 1965, and the 551st Strategic Missile Squadron was inactivated later that year. The land was turned over to the General Services Administration in 1965, transferred to private ownership in 1967, and has been used since 1979 as an auto salvage / vehicle recycling yard. It remains private property with no public access. The former military property is also documented in FUDS and environmental records as Former Lincoln AFB Atlas "F" Missile Site 1, FUDS Project Number B07NE058701.

Location, Landscape, and Site Description

Atlas F Site 551-1 is in rural Cass County, Nebraska, southeast of Elmwood and east of the Lincoln metropolitan area. The USACE Proposed Plan describes the site as 9.34 acres located about 2 miles south and 4.5 miles east of Elmwood. The surrounding land is agricultural, with adjacent privately owned parcels used for crops such as alfalfa, soybeans, and corn, and for livestock grazing. The missile complex was placed in a broad farm landscape typical of the Lincoln missile field: close enough to be supported from Lincoln AFB, yet far enough from the base and from the other launch complexes to increase survivability through dispersal.

The launch complex itself followed the Atlas F vertical-silo pattern. USACE describes the facilities as including an underground reinforced-concrete launch silo, a connecting underground launch control center, a water treatment plant, three water wells, a cooling tower, a septic tank with subsurface sand filter, a water-treatment holding pond, two corrugated-steel igloos, and two underground fuel tanks. In other words, 551-1 was not merely a hole for a missile. It was a self-contained launch installation with its own water, power, support, storage, communications, crew, and security requirements.

The site's surface appearance changed dramatically after military use ended. USACE records state that all permanent structures remained at the site after decommissioning and that, since 1979, the site has been occupied by Eastern Nebraska Auto Recyclers. The Lincoln AFB Legacy Project site page describes the topside as a large salvage lot and shows surface and underground views, including a pump building, access portals, the open silo, LCC features, blast-door hardware, the large site gate, and the remains of the silo door system. Those photographs are important because they document the unusual survival of major Atlas F structural features even after the site was stripped of operational military equipment and converted to industrial salvage use.

The property should be treated as private, potentially hazardous, and inaccessible without owner permission.

Strategic and Cold War Context

Site 551-1 existed because the United States was racing, in the late 1950s and early 1960s, to place survivable intercontinental ballistic missiles on alert before a Soviet first strike could threaten American strategic forces. Atlas was the Air Force's first operational ICBM. Atlas D had introduced the basic weapon into service, and Atlas E improved the system through dispersed individual sites and inertial guidance. Atlas F pushed the design farther by placing the missile in a hardened underground vertical silo.

The National Park Service summarizes Atlas F as the best of the Atlas missile types deployed and notes that 72 Atlas F missiles were fielded, with twelve each at Schilling, Lincoln, Altus, Dyess, Walker, and Plattsburgh. Lincoln's twelve Atlas F complexes formed a ring around Lincoln AFB. They were meant to reduce the vulnerability that came from concentrating missiles at a single base or in exposed aboveground facilities. A Soviet attack would have to find and destroy a number of dispersed, hardened sites, each capable of launching a nuclear-armed missile.

Atlas F still belonged to the first generation of American ICBMs. It used RP-1 kerosene fuel and liquid oxygen oxidizer, and the missile could not simply sit fully ready in the manner of later solid-fueled Minuteman missiles. The Atlas airframe was extremely thin and depended on internal pressure to maintain its shape. On alert, the missile was maintained and monitored in a ready state, but an actual launch sequence required the missile to be prepared, filled with liquid oxygen, raised by elevator to the surface, and fired from above the silo. That launch method increased survivability while the missile was underground but still exposed the weapon during the final launch sequence. This weakness helps explain why Atlas F was quickly eclipsed by Titan II and Minuteman systems.

The Cuban Missile Crisis was the most intense strategic moment of the 551st Strategic Missile Squadron's operational life. The Lincoln AFB Legacy Project history states that, by the October 1962 crisis, most of Lincoln's Atlas F missiles were operational and that 551st personnel worked long shifts because of the limited number of trained crews. For an Atlas F site, that alert posture did not mean the missile was continuously raised above the silo or continuously loaded with liquid oxygen. It meant the site, crew, missile, propellant systems, power, communications, and support equipment were maintained in a launch-ready posture so the missile could be prepared for launch if an authenticated order came. Kerosene fuel could be stored aboard or staged as part of the alert configuration, but the cryogenic liquid oxygen was not a permanent onboard load; it would be introduced during the launch sequence.

Construction and Activation

The Lincoln missile field was planned and built during the urgent expansion of the early American ICBM force. The Lincoln AFB Legacy Project history notes that Lincoln was designated as a missile base in 1959 and that the initial plan called for nine silos before three additional sites were added, bringing the total to twelve. Site 551-1 was one of those twelve.

USACE describes construction of the missile-site facilities as occurring in 1961 and 1962. The USACE Proposed Plan further states that the site was constructed during 1961-1962, decommissioned and dismantled in 1965, transferred to GSA in August 1965, and transferred to private ownership in March 1967.

The assigned Atlas F missile reached the site early in the fielding period. The missile was General Dynamics manufacturing number 34F, General Dynamics serial number 60-5557, and Air Force tail number 557. The missile was accepted on 1961-11-30 and delivered on 1961-12-20. Its destination was Lincoln Air Force Base, its mission was operational ICBM, and its site assignment was 551st Strategic Missile Squadron Site 1.

Strategic Air Command's official missile chronology places the first Series F Atlas operational-site acceptance for the 550th Strategic Missile Squadron at Schilling AFB, Kansas, and the 551st Strategic Missile Squadron at Lincoln AFB, Nebraska, in June 1962. This fits the broader pattern: construction, delivery, checkout, site acceptance, and operational readiness were overlapping steps, not a single moment. Site 551-1 had a missile accepted and delivered in late 1961, but the complex's final Air Force turnover and full operational integration occurred during the 1961-1962 fielding period.

Missile System and Technical Role

The SM-65F Atlas was a liquid-fueled, one-and-a-half-stage ICBM designed by Convair / General Dynamics. The Atlas F used an underground vertical silo-lift launch complex. In storage the missile stood vertically in the silo on an elevator. In a launch sequence, the missile was readied, fueled with liquid oxygen as required, lifted to the surface, and launched from the raised position. The system's advantage was that the missile was much better protected while stored below ground than the earlier Atlas D and Atlas E configurations; its disadvantage was that it still had to be exposed above the silo during the final launch sequence.

Public museum and historical sources describe the Atlas E/F weapon package as using the Avco Mark 4 reentry vehicle with the W-38 nuclear warhead. The Smithsonian National Air and Space Museum's Mark 4 reentry-vehicle record states that the Mark 4 was used on Titan I and Atlas E/F ICBMs and carried a W-38 warhead with a yield of about 3.75 megatons. The National Park Service article gives Atlas F a launch response time of approximately ten minutes and notes that the missile was held in a blast-proof silo-lift configuration. The NPS article describes the Atlas F as carrying a 4.5-megaton warhead; the Smithsonian Mark 4 page gives the more specific W-38 figure of about 3.75 megatons.

The crew relationship at 551-1 differed sharply from later Minuteman sites. A Minuteman Launch Facility was normally unmanned and controlled from a separate Launch Control Center miles away. Atlas F sites such as 551-1 were crewed launch complexes. The Lincoln AFB Legacy Project history describes a five-person missile combat crew: a missile combat crew commander, deputy missile combat crew commander, ballistic missile analysis technician, missile facility technician, and electric power production technician. Two guards remained topside. Crews served 24-hour shifts and operated within the site's own underground launch-control and support spaces.

The liquid-fueled Atlas demanded hands-on maintenance and constant attention. The missile and its ground equipment required pressure maintenance, propellant-system readiness, power generation, water and environmental systems, communications, security, and periodic testing. This technical complexity is one of the reasons the Atlas F force had such a short front-line life. It was a working ICBM, but it was also a transitional system between the exposed early Atlas era and the solid-fueled Minuteman model that could remain ready with much less day-to-day propellant handling.

Operational History

Site 551-1 served in the 551st Strategic Missile Squadron's twelve-site Lincoln missile field. The squadron was based at Lincoln Air Force Base from 1961 through 1965. The squadron's activation was 1961-04-01, reassignment on 1964-01-01 to the 98th Strategic Aerospace Wing under the 818th Strategic Aerospace Division, another reassignment on 1965-03-25, and inactivation on 1965-06-25. During its active period, the 551st's mission was to operate and maintain Atlas F ICBMs dispersed around Lincoln.

The Lincoln field's daily operation depended on constant movement between the base and the sites. The squadron's administrative and maintenance activities were centered at Lincoln AFB, including the Missile Assembly and Maintenance Shop. Crews were briefed at the base, dispatched to the missile complexes, and then lived and worked inside their assigned sites for alert duty. The surface and underground spaces at 551-1 were therefore not dormant storage areas. They were active duty stations, with crew members, security guards, support systems, and a nuclear-armed missile requiring continuous readiness.

By the time of the Cuban Missile Crisis in October 1962, Lincoln's Atlas F field was part of the nation's emergency nuclear posture. Most of the Lincoln Atlas F missiles were operational by the crisis and that 551st personnel worked long two-day shifts because of the limited number of trained crews. Site 551-1's assigned missile had already been accepted and delivered in late 1961, so the site fits the group of early Lincoln Atlas F complexes that formed the squadron's operational capability during the crisis period.

The site's operational role was deterrence rather than combat use. Its purpose was to remain ready and credible, not to launch. Every maintenance evolution, inspection, guard shift, power-system check, communications test, and propellant procedure supported the same strategic premise: an adversary could not count on destroying American nuclear forces before they could respond. At 551-1, that national strategy was embodied in concrete, steel, cryogenic propellant systems, blast doors, underground crew spaces, and the delicate stainless-steel Atlas missile standing inside the silo.

Deactivation and Disposal

Site 551-1 was decommissioned in 1965. This came during the rapid retirement of the first-generation Atlas force. Atlas F had been an important bridge to hardened, dispersed ICBM alert, but by 1965 the Air Force was moving to newer systems. Titan II could launch from within its silo and did not require liquid oxygen. Minuteman was solid-fueled and far easier to keep on alert. As these systems matured, the early Atlas squadrons became costly and operationally obsolete.

Strategic Air Command's chronology records the inactivation of the last remaining Atlas ICBM squadrons on 1965-06-25, including the 551st Strategic Missile Squadron at Lincoln AFB. That date should be distinguished from the site decommissioning date. The individual complex could be decommissioned before the administrative inactivation of the squadron. Likewise, missile removal, equipment removal, property transfer, and later environmental response occurred on still other timelines.

USACE records state that the property was turned over to the General Services Administration in 1965. The 2011 USACE Proposed Plan gives August 1965 as the point when the site was transferred to GSA and placed in excess status. In March 1967, it was transferred to private ownership. USACE also states that the land has been used as an auto salvage yard since 1979. All permanent structures remained at the site as of the 2015 USACE fact sheet, but operational missile equipment had been removed or salvaged.

The site's disposal history was not driven by later strategic arms-control treaties in the same way as many Minuteman and Peacekeeper facilities were. Atlas F was withdrawn before the major post-Cold War treaty-demolition era. Instead, 551-1 represents an earlier disposal pattern: missile and military equipment removal, GSA excess-property handling, private sale, industrial reuse, and later environmental investigation under the FUDS program.

Environmental Investigation and Cleanup

The environmental history of 551-1 is unusually well documented. USACE identifies the site under the Formerly Used Defense Sites program as Former Lincoln Air Force Base Atlas "F" Missile Site 1, Elmwood, Nebraska, FUDS Project Number B07NE058701. The site is also listed by EPA under the name LINCOLN (EX) ATLAS "F" FAC S-1, EPA ID NEN000703247, at 35408 O Street, Elmwood, Cass County, Nebraska. EPA's Superfund profile lists it as not on the National Priorities List and as NFRAP / no further federal action for that EPA site profile, while USACE and Nebraska environmental documents separately document the FUDS groundwater response.

USACE states that TCE was used during operation and decommissioning of the former missile site. Environmental investigations were performed from 1989 to 1995, including a site investigation, limited field investigation, and supplemental water-supply sampling. Later work was delayed when access to the property was denied until 2005. From 2005 through 2008, USACE conducted remedial investigation and feasibility study work. Additional characterization and pilot testing followed in 2009 and 2010.

The 2011 USACE Proposed Plan states that the entire site was occupied by Eastern Nebraska Auto Recyclers and that adjacent lands were farmland. It identifies TCE as the primary contaminant of concern and also identifies cis-1,2-DCE, vinyl chloride, and 1,2-DCA in groundwater. It describes two distinct TCE groundwater plumes: a shallow unconfined groundwater zone at depths of about 10 to 40 feet below ground covering about 597,000 square feet, or 13.8 acres, and a deeper regional drinking-water aquifer at depths of about 70 to 90 feet below ground covering about 620,000 square feet, or 14.1 acres. TCE was not detected in unsaturated soil samples, so the cleanup focus was groundwater.

USACE and NDEE documents describe several response actions. The production well in service at the site was not to be used for drinking water. Bottled water was supplied to the property owner, and in November 2010 the site was connected to a rural drinking-water supply line. Three potable-water wells installed at the time of missile-site construction were abandoned and sealed. During 2010 field activities included 32 membrane interface probe borings, 10 soil borings, 29 new monitoring wells, groundwater sampling from 53 monitoring wells, and two aquifer tests. The preferred cleanup alternative in the 2011 Proposed Plan was enhanced in-situ bioremediation, including injection of soybean oil to stimulate naturally occurring bacteria to break down contaminants in groundwater, along with aquifer-use restrictions and a replacement water supply.

Nebraska Department of Environment and Energy material published for 2025 shows that the site remained part of ongoing regulatory attention in the modern period.

Current Status and Site Use

Atlas F Site 551-1 is decommissioned, privately owned, and reused as an auto salvage / vehicle recycling property. It is not an active military installation and is not a public historic site. USACE records state that all permanent structures remained at the site as of its 2015 fact sheet, but operational missile systems and much scrap metal had been removed. The Lincoln AFB Legacy Project photographs show the surviving surface and underground remains, including parts of the silo, LCC, access portals, pump structures, gate features, and door hardware.

The visible surface site is dominated by salvage-yard use. The surrounding landscape remains agricultural. The underground complex is hazardous by nature: deep open shafts, deteriorated concrete and steel, confined spaces, potential flooding, poor air quality, and environmental contamination are all realistic dangers at former missile sites. The site is private property and should not be entered without permission.

Chronology

• 1959 Lincoln was designated for an ICBM missile mission; the field was later expanded to twelve Atlas F sites.
• 1961-04-01 The 551st Strategic Missile Squadron was activated.
• 1961-11-30 The assigned missile, GD manufacturing number 34F / GD serial 60-5557 / AF tail 557, was accepted.
• 1961-12-20 Missile 34F was delivered for the Lincoln AFB / 551st SMS operational ICBM mission.
• 1961-1962 USACE records describe construction of the missile-site facilities during this period.
• 1962-06 SAC accepted the first Series F Atlas ICBM operational sites at the 550th Strategic Missile Squadron, Schilling AFB, and the 551st Strategic Missile Squadron, Lincoln AFB.
• 1962-10 During the Cuban Missile Crisis, operational 551st SMS Atlas F sites were held at a high level of alert; for Atlas F this meant launch-ready posture, not continuous aboveground or liquid-oxygen-loaded status.
• 1964-01-01 The 551st SMS was reassigned to the 98th Strategic Aerospace Wing, 818th Strategic Aerospace Division.
• 1965-06-25 SAC inactivated the 551st Strategic Missile Squadron.
• 1965-08 The site was turned over to the General Services Administration and placed in excess status.
• 1967-03 The former missile site was transferred to private ownership.
• 1979 The site began use as an auto salvage yard, according to USACE.
• 1980-04-26 Former Site 551-1 missile 34F launched successfully from Vandenberg AFB SLC-3E carrying the NAVSTAR 6 / GPS 6 navigation satellite.
• 1989-1995 Environmental investigations were performed at the site, including site investigation, limited field investigation, and water-supply sampling.
• 2005-2008 USACE conducted remedial investigation / feasibility study work after access to the property was obtained.
• 2010 USACE field work included membrane interface probe borings, soil borings, new monitoring wells, groundwater sampling, and aquifer tests; the site was connected to a rural water supply and former potable wells were sealed.
• 2011-09 USACE issued a Proposed Plan for groundwater cleanup using enhanced in-situ bioremediation, aquifer-use restrictions, and replacement water supply.
• 2015-04-07 USACE published its public FUDS fact sheet for Former Lincoln AFB Atlas "F" Missile Site 1.
• 2025 Nebraska Department of Environment and Energy material documented direct-push work for in-situ enhanced bioremediation injections into aquifers beneath the former Site 1.

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