Between 1956 and 1966, the National Park Service (NPS) had 95 visitor centers, 216 utility buildings, 257 administrative and service structures, 575 campgrounds, 1,239 park housing structures, and 2,767 miles of new and repaired roads constructed throughout the national parks, among other amenities. All structures featured a distinctive modernist park style. Spurred by a comprehensive program known as Mission 66, these new additions were built to address problems plaguing the parks, including outdated buildings that could not accommodate the expected 31 million increase in visitors by 1966. The program had its controversies—after all, it was a great departure from the traditional rustic style of park service architecture, it re-imagined the role of parks for the public, and it caused friction with the mission of conservationists and environmentalists—but it succeeded in bringing the national parks into the modern era, transforming how we see parks even today.

The end of World War II drastically changed the American landscape—the housing shortage for soldiers returning home led to a huge housing boom that led to the creation of suburbs outside city limits; the creation of strip malls allowed for people to access many conveniences in one place; car travel increased thanks to the expansion of the interstate highway system; annual individual earnings increased nationally; and Americans now had time to spend on leisurely activities, such as visiting national parks. In 1940, 17 million people visited national parks. In 1956, the number had jumped to 49 million. The NPS expected the number to grow to 80 million by 1966. The actual number was much higher, at 127 million.

However, the parks were in terrible shape in the years leading up to 1956, when Mission 66 was implemented. It became a national scandal of sort, with op-eds, editorials, and essays being published with regularity lamenting the lack of parking space, neglected visitor amenities, and outdated facilities. Bathroom lines were long, traffic jams were a necessary evil, and many could not find overnight accommodations. NPS Director Newton Drury noted that “Facilities and services to the public during 1945-46 were not—and could not be—up to the usual park standards.”

Parks staff were working with limited budgets, staff, and construction materials, a change that also occurred during World War II. It didn’t help matters that New Deal work relief programs like the Civilian Conservation Corps and the Works Progress Administration, which accomplished a lot of projects in many national parks over the years, were disbanded in 1942.

Some critics were concerned that Congress would not appropriate the necessary funds (estimated to be $250 million over the course of five years) to revitalize the parks to accommodate the growing number of tourists (and their cars). In 1953, commentator Bernard DeVoto published an article in Harper’s, summarizing the issue by stating that “A lack of money has now brought our national park system to the verge of crisis.”

Compounding these issues was the increase in car travel following the war, a new trend that created significant problems for the Park Service. By 1950, 99 percent of people entering the parks were arriving in automobiles, but there were not enough roads or parking space to accommodate them.

How to solve these problems created a conundrum for the NPS until 1954, when three years into his tenure as NPS director, Conrad L. Wirth proposed a 10-year capital campaign to bring the national parks into the modern era by 1966, the 50th anniversary of the NPS. The name, Mission 66, evoked a sense of immediacy felt during World War II and encouraged urgent action. In the proposal, Wirth and its other creators asked Congress to increase appropriations for the national park system as soon as possible, and that they continue financial support for the next 10 years. Congress accepted, and it agreed to supply the NPS with over $700 million for 10 years (the real number ended up being more than a billion dollars).

While the creators of Mission 66 saw the plan as a way to preserve the national parks while accommodating the influx of visitors, some, however, believed Mission 66’s construction plans were encroaching and endangering the existing wilderness in parks. Rebuking one accusation that the NPS was not paying attention to wilderness preservation, Wirth attempted to further elucidate the purpose of the new construction in the parks, noting that these new public spaces were “zones of civilization in a wilderness setting.”

The visitor center served as the entry point to national parks, where people could orient themselves, get introduced to the park through audiovisuals, maps, and guides, and purchase merchandise to remember their trip. They were sited in places where visitors would have the best views. The visitor centers of Mission 66 featured typical aspects of modernist architecture adapted for the parks: a low form with an emphasis on horizontality so as not to distract from the landscape, subdued colors, and the use of post-war building materials and practices such as steel, concrete, glass, and curtain walls, which were cost-effective and efficient.

Comfort stations and park administration buildings not open to the public featured standard plans that could be easily replicated. Park employee single-family housing were typical ranch-style houses with several options for customization.

The point that everything in Mission 66 sprung from was change. The park service was responding to the modernization of American society and its effects on the national parks. It swapped out an outdated national park model for one that served visitors more effectively, thereby allowing them to experience the parks as NPS employees intended them to. Some people saw Mission 66 as a cloak covering the real result—a compromise of the natural environment so that people could enjoy nature from their cars, not on foot.

In reality, though, Mission 66 was simply an adjustment to a fate that was already happening. Millions of people were coming to the parks each year, and those millions were arriving in cars and required modern amenities. The chief landscape architect of Mission 66, Thomas Vint, believed that in order to preserve the parks, the parks needed to accommodate the people.

When 1966 arrived, many projects and buildings were still in the works, so the NPS extended the program under a new name, called “Parkscape USA,” that ran from 1967 to 1973.