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From Coal to the Cold War: Cougar Mountain Regional Wildlife Park’s Former Nike Missile Sites

This is the second in a series of blog posts celebrating American Archives Month 2016, using King County records to tell stories on Washington state’s theme of “We Love Parks.” For more, see “Athletes with Disabilities: King County Parks as a Recreation Pioneer” and “Lake Wilderness Lodge: Mid-Century Modern, Pacific Northwest Style.”

At the center of the Seattle Defense Area, King County was home to at least seven Nike missile installations between 1956 and 1974, most of which became county or city parks after decommissioning. The former Nike sites at Cougar Mountain and Lake Youngs were both taken over by King County Parks and developed into recreational areas for the benefit of the public.


Bird’s-eye photograph of Cougar Mountain, 1982. Taken from near just southeast of the intersection of SE May Valley Rd & SR 900.
Series 1629, Box 1, Folder 1.

Locating Missile Sites

The rapid stockpiling of American and Soviet missile arsenals that came to define the Atomic Age raised the possibility of sudden, decisive strikes that all but guaranteed long-term, widespread devastation for the government caught off-guard. American resources were invested not only in civilian defense, but into building an arsenal, ensuring the promise of mutually assured destruction and deploying dozens of defensive conventional and nuclear missile silos around major coastal cities and military installations.

Siting the installations during early planning phases was problematic; launch sites needed to be located in defensive rings around major cities and critical sites, but also required 119 acres per site. By the time the Ajax and Hercules sites of the Seattle Defense Area were built, architect Leon Chatelain, Jr., had designed underground sites that not only provided first-strike protection to the command and control facilities, but also decreased the necessary amount of land to 40 acres and allowed the sites to be located closer to the cities they defended.

Building a Park

King County acquired the former Nike sites through multiple transactions between the 1960s and the 1980s. The current site of Petrovitsky Park was once part of the Lake Youngs dual launch and control sites, stocked with Ajax surface-to-air missiles and operational between 1956 and 1961. Grandview Park and Kent Mountain View Academy in SeaTac are located on land acquired from King County after the Army decommissioned the former site of S-43, the Kent/Midway Ajax launch installation.

Above, 1965 Aerial Survey images from the King County Road Services Map Vault. Left to right: Lake Youngs (map no. KCAS-1965.23.05); Kent/Midway (map no. KCAS-1965.22.04)

Arguably the crown jewel of the King County Parks system, Cougar Mountain Regional Wildland Park encompasses the sites of the former Ajax missile launch and control facilities known as S-20. Like Petrovitsky Park, the Cougar Mountain area had experienced active coal mining in the late 19th and early 20th centuries and became anti-ballistic missile installations during the late 1950s and early 1960s. During construction of the underground missile storage vaults, Army contractors reportedly filled two open mine shafts with concrete to seal the openings and stabilize the area.

Cougar Mountain Launch Site Park Plan

Cougar Mountain Launch Site Park Plan, 1981. Series 1876 – Parks maintenance subject files, box 2

Deactivated in 1964, both the control and launch sites at Cougar Mountain were acquired by the King County Parks and Recreation Division and turned into the upper and lower park areas in 1983. In 1993, Parks partnered with the Army Corps of Engineers and government contractors on an environmental project at the former control site: removing the mess hall, latrine, and assembly and test buildings; pumping water out of the missile vaults; and seeding the launch area to cover it with grass. Some of the upper site remains.

Aerial photographs of S-20 Cougar Mountain/Issaquah, ca. 1970s-1990s. Left: control site near Anti-Aircraft Peak; right: launch site off of Clay Pit Rd.
Series 900, Rolls 25 and 26.

King County continued to acquire land around these two initial sites, with the goal of building the park into a large public recreational area, close to urban populated areas and providing access to a wide variety of wild natural areas within the context of the region’s developmental history. “The green spaces within urbanized areas are not created or preserved because the land underneath is unsuitable for urbanization,” proclaimed a 1981 study by the Parks and Recreation Division:

Instead, the green spaces are there because the overall metropolitan complex needs them and ‘forward thinking decision makers’ have preserved them. . . . It is not any individual specific scene or composition that is captivating [at Cougar Mountain]; rather, visitors are taken by the mountain’s aggregate extent, its variety and landscape complexity and its many-acred largeness.

Miles of trails, expansive views of the region, and distinctive terrain characterize this landscape, and it is one of the few sites in King County with such an abundant diversity of native Washington plants. Today, Cougar Mountain Regional Wildland Park contains 3,100 acres of public wildland, connected to Squak Mountain State Park for a total of 5,000 acres of land protected for the enjoyment of all.

Selections from Series 467, Photograph files of the King County Parks System, Cougar Mountain, Box 2, Folder 24.


Cougar Mountain Regional Wildland Park in King County, Washington,

Fred Weinmann, “Cougar Mountain Regional Wildland Park—Marshall Hill Trail, DeLeo Wall and Redtown Meadow — April 20,” Washington Native Plant Society (Seattle, WA),, updated 3 Jul 2016.

John C. Lonnquest, David F. Winkler, and Julie L. Webster, “To Defend and Deter: The Legacy of the United States Cold War Missile Program” (Washington, DC, 1996).

King County Archives records cited

Series 467- King County Parks System – Photograph files, Box 2, Folder 24: “Cougar Mountain”

Series 900 – Department of Natural Resources and Parks – Aerial photographs:

Roll 25, Cougar Mountain Upper, 1″=50′
Roll 26, Cougar Mountain Lower, 1″=50′

Series 1629 – Office of Information Resource Management: Service Development / Printing and Graphic Arts – Photographs: Negatives, Box 1, Folder 1

Series 1876 – Department of Natural Resources and Parks – Parks maintenance subject files, box 2:

Study: “Cougar Mountain Regional Park,” King County Parks and Recreation Division (Seattle, WA, 1981).

Memo from Steve Williams to Randy Schroers, Bud Parker, and Ron Erickson (30 Nov 1992).

Related King County Resources

October is American Archives Month!
The theme chosen by the Washington State Archives for 2016 is “we love parks.” This is the second of a series of four posts from the King County Archives on the history of King County Parks.

One Comment

  1. Christopher Anderson Christopher Anderson October 29, 2016

    Excellent article. I like that the park system was able to re-purpose the surplus military facility. This was very well organized, written and the photos are beautiful.

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