Get to know South Dakota Modern


Katie Wasley


South Dakota State Historic Preservation Office


Regional Spotlight, South Dakota
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Historical context for modern sites in South Dakota is still in its fledgling stages. The three articles in this regional spotlight were contributed by staff members of the South Dakota State Historic Preservation Office (SHPO). Our office knows that the Modern period will be an increasing part of our work to evaluate historic significance of built resources and provide preservation guidance and resources to property owners and local governments. Having wide gaps in the state’s architectural history will do a disservice to modernist styles and architectural forms, and to the work of late-20th century architects. We have been expanding our architect files and have contracted for contextual histories of postwar architecture and of single-family housing from 1950 to 1975, but there is a lot more yet to do. This is starting to filter into local communities, with historic preservation boards/commissions in Sioux Falls and Rapid City recently working on survey and planning projects that compiled information on the midcentury period. Recognition of modern resources within the general population of South Dakota is still a hill to climb. We also assume that, broadly speaking for those outside the state, awareness of this history is likely negligible. Writing this set of spotlight articles has served as a way for our staff to expand their knowledge about Modernism, and it is our humble way to introduce South Dakota to the wider Modern Movement audience. 

Get to know South Dakota Modern Part One
Modernism in the Black Hills

The Black Hills of South Dakota have long been known for their picturesque views, monumental sculptures, national historic districts, and abundant outdoor activities.  While many of these features draw numerous tourists to the Black Hills region, the modern architecture hidden within the hills is testament to the rise of leisure and outdoor recreation in the United States in the mid-20th century.  More and more tourists were traveling by automobile, which were more affordable and common.  This brought an increase in the use of public resources like road networks and the national and state park systems.  

With the rapid increase in travel and leisure, government agencies and towns in established tourist areas raced to build and update attractions and accommodations. To help expand public resources for recreation and tourism, the federal government set up several programs including the Federal-Aid Highway Act of 1956; the creation of the Recreation Advisory Council in 1962, an interagency group that in 1964 promoted the funding of scenic roads and parkways; and the founding of the Bureau of Outdoor Recreation in 1962. One of the key federal acts from this era that influenced recreational architecture throughout federal, state, and local levels was the National Park Service’s Mission 66.

After World War II, the National Park system lacked the attention and funding needed to keep up with the increasing numbers and demands of visitors.  In 1956, by framing their funding needs into a mission style request, the National Park Service was able to secure Congressional appropriations for the park system that would last through 1966.  The funding from this program went into park improvements such as repairing roads and building new facilitates for visitors and staff. During this construction era, the National Park Service adopted a new architectural style that came to be called the Park Service Modern style. This style retained the earlier rustic-style approaches of blending new construction with the surrounding setting, but also adopted plain and streamlined aesthetics to keep the attention on the natural beauty of the buildings’ surroundings. Shortly after the initial success of Mission 66, this architectural concept was adopted on state and local levels.

The Black Hills National Forest and Custer State Park had been established in 1897, Wind Cave National Park in 1903, and Jewel Cave National Monument in 1908, with Needles Highway and Mount Rushmore joining them in the 1920s. In the 1930s, New Deal era improvements through the Civilian Conservation Corps and other programs injected a lot of new tourist facilities. On this solid foundation, increasing tourist demands of the postwar era greatly affected the Black Hills.  Custer State Park recorded having over one million visitors in 1961. Although some architectural works, like the Mission 66 visitor center at Mount Rushmore, are already lost, many of the structures built during this time are still present for the public to visit and view.  

Two constructions of this era that are likely not well-known outside of South Dakota (or, frankly, inside South Dakota) are the Keystone Wye Bridge and the Pactola Visitor Center.

The Keystone Wye Bridge

The Keystone Wye Bridge is a three-tiered bridge located in western Pennington County at the interchange of U.S. Highways 16 and 16a, the former a main highway south from Rapid City (pop. 75,258 in 2019) towards Custer and the Crazy Horse monument, and the latter heading towards Keystone and Mount Rushmore before becoming the scenic Iron Mountain Road (Peter Norbeck Scenic Byway) with its “pigtail” bridges of stone and log. The Keystone Wye Bridge was built to help the flow of traffic from Rapid City—where tourists from across the country and world arrive by interstate or airplane—to Mount Rushmore, Custer State Park, and other attractions, and has therefore become a gateway experience for millions of people visiting the park areas of the southern Hills. The arched glue-laminated timber bridge is also a rare sight to see for bridge construction in South Dakota.

Designed by Clyde Jundt and Kenneth C. Wilson for the South Dakota Department of Transportation (SDDOT), the bridge began construction in 1966 and was dedicated in October 1968. The designers wanted to make sure that the bridge would harmonize with the natural beauty of the area surrounding the interchange and so chose timber construction. To begin construction of the arches for the top-tier of the bridge, Jundt and Wilson traveled to Oregon to pick the Douglas fir that the glue-laminated arches would be constructed from. The lumber was taken first to California and pre-treated with a preservative, then to Timber Structures Inc. in Portland where the boards were planed, scarped into 91-ft. sections, glued and laminated into arches, trimmed, and fitted with steel end caps. Construction on-site started with clearing timber, blasting larger rocks, preparing grading and drainage, and building foundation footings of reinforced concrete.

When it came time to assemble the bridge, the project faced unique challenges. While transporting the arch components the ten miles from the railroad depot in Hill City to the site, one of the trucks carrying three of the arch components tipped over on a curve.  Rather than risk the structural integrity of the bridge, SDDOT ordered three new arch components to be constructed. The three rejected arches were later repurposed as a memorial arch installation and eventually moved to a location north on highway 16. Then, in order for the top tier of the bridge to come out as designed, both sides of the smaller arch components had to line up perfectly after being placed in their cement bases in order for the larger arches to be formed correctly. Fortunately, all the measurements and plans came together as designed. The bridge cost over $2 million and was under construction for over two years. The general contractor was Summit Incorporated of Rapid City, who hired bridge contractor George Moore of Moore Construction Co. to oversee the project.

After the bridge’s completion, SDDOT put out a half hour long promotional film with their footage of the construction from design stages through to the dedication.  The film has been digitized by the South Dakota State Archives and is viewable through their digital collections—“The Keystone Wye,” produced by Nauman Films, Inc. of Custer.

Additional historic images are also available through the Archives.

Pactola Visitor Center

The Pactola Visitor Center is located along U.S. Highway 385 that serves as a much-needed rest stop for weary travelers as well as providing a picturesque view of the Pactola Reservoir within the Black Hills National Forest. The Pactola Dam was built on Rapid Creek by the U.S. Bureau of Reclamation starting in November 1952 and finishing in August 1956. On average, the lake has over 1,200 acres of surface area and sixteen miles of shoreline. 

The Pactola Visitor Center sits on the tall, east shore of the lake towards the southern end of the dam. This unique building was built in 1969 by the young people working for the Boxelder Job Corps Civilian Conservation Center near Nemo, S.D. During this period, the architects for Region 2 of the USDA Forest Service were Wes Wilkson and Dave Faulk. According to correspondence with the Forest Service, construction took longer than originally expected due to the area being quite rocky. The official dedication ceremony for the visitor center took place in August 1976 with addresses by Governor Richard Kneip, U.S. Representative James Abnor, and Forest Service chief John McGuire.

The Pactola Visitor Center is a modified A-Frame style building with skylights in the monitor created by the offset ridge and a wide dormer with two sets of windows on its southwest slope.  The A-Frame architectural style rose to popularity in the 1950s when people began to use this style as vacation homes or cabins. State and federal agencies also began to use this style starting in the mid-1960s as visitor centers and temporary lodging. The steepness and height of the visitor center’s roof reflects the steep landscape on that edge of the lake and surrounding hills. Southeast of the main building is a smaller building with visitor restrooms. Both are constructed from a combination of stained lumber and uncoursed local stone, materials which carry into the interior spaces as well. North of the building is a parking area, patio and picnic area with stone walls. On the lakeside west end of the main building, there are steps with stone walls running down to a lower patio overlooking the lake.

The Forest Service has begun looking for vendors to operate this building after a decline in the budget for visitor centers in recent years.

Photographs from the Black Hills National Forest collection, including more building and construction photos, are available through the digital collections of the Leland D. Case Library, Black Hills State University, Spearfish.

Other Sites from the Era

Several other buildings and structures were also built for federal lands in the Black Hills during this time of increased automobile tourism. They also reflect evolving Forest Service and National Park Service approaches to visitor services and interpretation, as well as increased staffing for supervision and conservation work.

The Old Harney District Office of the Black Hills National Forest, built in 1964, is located in Hill City.  This building is a Ranch style building with a low-pitched roof, projecting roof beams, and stone veneer accent walls.  In 2007, the building was sold to the city of Hill City and now serves a dual purpose as the location of the CCC Museum of South Dakota and as the Hill City Visitor Information Center. The Harney District Office was replaced by the Mystic District Office complex.  

In 1979-1980, the Black Hills National Forest built new superintendent headquarters west of Custer. It also serves as the Hells Canyon Ranger Station. The complex includes three hexagonal buildings with low-pitched monitor roofs, ribbons of windows, and stone veneer accents that are connected by hallways and arranged in an equidistant group around a central courtyard.

The Jewel Cave National Visitor Center is located at the Jewel Cave National Monument site and is owned by the National Park Service. The construction began in 1966 and took over five years to complete. The visitor center was officially dedicated in May 1972. This visitor center is an example of the Park Service Modern style that came to fruition in the Mission 66 era. Much like the Pactola Visitor Center, this visitor center provides a stunning view of the Black Hills National Forest while providing access to Jewel Cave and hiking trails to the forest. Visitors enter the complex descending by stairs or now by ramp to a central courtyard with the main offices, museum, and shop at the west end, a restroom wing, and a separate offshoot building for an elevator entrance to take tourists down to the cave. There are staff housing and maintenance facilities in the woods to the north of the parking area.  The historic cave entrance and a 1930s ranger cabin are located 0.7 miles to the northwest.


Allaback, S. (2000). Mission 66 Visitor Centers: The History of a Building Type. Washington, D.C.: U.S. Department of the Interior.

Arch Professionals, & Mead & Hunt. (2018). Historic Context of A-Frame Architecture in Boulder County. Boulder County Land Use Department.

Black Hills National Forest. (2018, September). Request for Expression of Interest Regarding Concession Permit Development and Use of the Pactola Visitor Center Facility.

Carr, E. (2007). Mission 66: Modernism and the National Park Dilemma. Amherst: University of Massachusetts Press.

CCC Muesum of South Dakota. (n.d.). Nemo's Boxelder CCC. Official CCC Museum of South Dakota.

Dennis, M. L. (n.d.). Keystone Wye Bridge. (G. Esperdy, & K. Kingsley, Editors) SAH Archipedia, Society of Architectural Historians.

Duwadi, S. R., & Ritter, M. A. (1997). Timber Bridges in the United States. Public Roads, 32-40.

Grosvenor, J. R. (1999). A History of the Architecture of the USDA Forest Service. United States Department of Agriculture, Forest Service, Engineering Staff.

Lead Daily Call (SD), July 15, 1968.

National Park Service. (2021, June 5). History & Culture.

Randl, C. (2020, December 3). “The Mania for A-Frames.” Old House Online:

South Dakota Game, Fish & Parks. (n.d.). Custer State Park History.

The Keystone Wye (cir. 1970). [Motion Picture], Nauman Films, Inc., South Dakota State Archives, Pierre.

Tupper, S. (2018, November 26). Ideas Sought for Future of Pactola Visitor Center. Rapid City Journal.

Zimmy, M. (2020, March 4). Landmarks: The Keystone Wye and the Highway 16 Arch. South Dakota Public Broadcasting.

About the Author

Katie Wasley has served as a Historic Preservation Specialist since March 2021 for the South Dakota State Historic Preservation Office. She is a graduate of Ball State University (M.A. in Anthropology, 2019), Eastern Washington University, and Cottey College.

Get to know South Dakota Modern is part of the Docomomo US Regional Spotlight on Modernism Series, which was launched to help you explore modern places throughout the country without leaving your home. Previous spotlights include Chicago, MississippiMidland, MIHoustonLas VegasColoradoKansasPittsburgh, and Milwaukee. Have a region you'd like to see highlighted? Submit an article.

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Get to know South Dakota Modern Part Two:
Modernist Standouts among the Catholic Churches in South Dakota