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Presenting Nature
MENU
Design Ethic Origins
(1916-1927)
Design Policy & Process
(1916-1927)
Western Field Office
(1927-1932)
Decade of Expansion
(1933-1942)
State Parks
(1933-1942)
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Presenting Nature:
The Historic Landscape Design of the National Park Service, 1916-1942 |
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IV. THE WORK OF THE WESTERN FIELD OFFICE, 1927 TO 1932 (continued)
DESIGN OF PARK ROADS (continued)
TUNNELS
Tunnel construction in the national parks where slopes were too steep to carry a road drew heavily from nineteenth-century railroad engineering. Of concern to the landscape engineers was the character of the portals, which visually connected the tunnel with the natural surroundings of the park. The earliest tunnels in the national parks imitated the arched openings of caves or rock outcrops that formed natural bridges. Such natural features held great romantic appeal for nineteenth-century travelers and were absorbed into the picturesque imagery of the wilderness. Formations such as Arch Rock in Yosemite and Crystal Cave in Sequoia were subjects of popular interest. It is not surprising that the naturalistic arched form was introduced in the portals for artificial tunnels along the Columbia River Highway in Oregon. Here motorists traveled through rough arched openings carefully blasted out of the natural bedrock and cliffs to simulate nature's handiwork. Longer tunnels had a gallery of openings through which travelers could catch glimpses of scenery.
From a landscape standpoint, by creating tunnels through buttresses of hard rock, road designers could avoid extensive blasting and the resulting disfigurement of the rock cliffs. By giving the openings the naturalistic character of a cave entrance, the designers harmonized the tunnel with the natural scenery and enhanced the picturesque qualities of the road.
Tunnels were common on steep rock inclines such as the transmountain roads in Glacier. Park road builders carved such tunnels to avoid extensive excavation and to keep down the amount of material that once removed would have to be placed nearby or transported away. Portals were hewn out of the natural rock, adding to the rustic character of the landscape. In the 1920s, tunnels with natural rock portals were incorporated in early park roads, such as the Going-to-the-Sun Highway in Glacier National Park, and on park trails, such as Glacier's Ptarmigan Trail. They appeared at the approaches to the Hetch Hetchy Dam in Yosemite and the Kaibab Suspension Bridge (1928) in Grand Canyon. Even after masonry portals were introduced in the late 1920s, the idea of viewing galleries remained popular. The Zion-Mount Carmel Tunnel (1930) in Zion National Park was built with a gallery of viewing bays from which motorists could view the spectacular scenery.
As tunnels increased in length and were excavated from various types of rock, the desirability of leaving an exposed rock arch at the entrance was ruled out by practical factors such as the nature of the local stone or difficulty in attaining a naturalistic arch. Techniques for staining concrete portals or facing them with stonemasonry to appear rustic or naturalistic emerged. The portals of the Wawona and Zion-Mt. Carmel tunnels were among the first to incorporate new techniques.
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| Mary's Rock Tunnel on Shenandoah National Park's skyline Drive was constructed in the early 1930s. The tunnel was blasted through 610 feet of granodiorite. Portals were cut out of the rock in an arched shape and the rock left in its natural state. The temporary shelter and construction materials in front of the south portal were part of the construction camp, which was placed in the right-of-way to avoid damage to areas surrounding the road, steep barren areas on the slopes above the portal were later planted with black locust, laurel, and other native plants. (National Park Service Historic Photography Collection) |
The aesthetic approaches to stonework that had been explored in the construction of bridges and culvert headwalls were carried over into the construction of tunnel portals. Weathered stone was used to form arch rings for the portals and was laid up in random, irregular, and rough courses to abut the surrounding earth and natural rock. The exposed rock lining of tunnels would, for practical reasons, give way to concrete linings and carefully designed drainage systems. Problems with water seepage causing serious freezing of roadways inside the tunnels in the winter necessitated the installation of concrete liners.
THE WAWONA TUNNEL AND OVERLOOK
Yosemite's Committee of Expert Advisers became involved in the planning for a route to connect Yosemite Valley with Glacier Point by way of the new Wawona and Glacier Point roads, which intersected at the Chinquapin Intersection. Although they recommended that a road of a reasonable grade be built without any tunnels, such an approach was not feasible. Plans for the construction of the 4,200-foot Wawona Tunnel proceeded, posing many problems from the landscape standpoint. The result was not only an engineering feat but also a design solution that would influence the design of other areas where the construction of a tunnel was inevitable. The desire to create a dramatic overlook at the end of the tunnel and the practical problem of disposing of the extensive amount of fill excavated from the tunnel led to a solution whereby the excavated material was retained by a hand-laid embankment to create a terrace for parking and viewing. A simple curvilinear terrace was formed beside the roadway at the end of the tunnel, and an island graded to separate the overlook from the road and to control the flow of traffic on and off the road. The overlook provided a parking area bounded by a curb, sidewalk, and ribbonlike parapet wall. Upon exiting the tunnel, visitors would get their first expansive view over the valley and would be able to pull aside and leave their automobiles to contemplate or photograph the scene. [48]
Committee chairman Frederick Law Olmsted, Jr., reported,
From the "landscape standpoint" the most serious issue of the plan for the tunnel and road into the Valley was the great width and height of the permanently barren rock-fill in the steeper parts of the valley-side east of the tunnel. Rock excavated from the tunnel would be shattered into relatively small stones (one man size or less) and would take a slope of repose of about 1/2 to l. The bank produced below grade would vary from about 200 feet in height and 300 feet in width at the parking space for the valley view (near the east portal of the tunnel), to about 100 feet in height and 150 feet in width just east of the parking space. The bank would diminish in size as it reached the lower end of the road. The coarseness of the fill would prevent any growth of trees or bushes on the slopes. The scattering of rocks at great velocity along such a slope threatened existing trees and vegetation. The committee recommended construction of a hand-laid rock embankment. [49]
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| Inspiration Point at the end of the Wawona Tunnel completed in 1933 was one of the first successful efforts to integrate engineering and landscape concerns in the development of a scenic overlook. Fill excavated from the tunnel was used to create an overlook complete with a parking area, island, sidewalk and curb, protective guardrail, and one of the most spectacular and memorable views of Yosemite valley (Bridalveil Fall is in the distance at the right). (National Park Service Historic Photography Collection) |
The committee was interested in efforts to artificially darken, and thereby disguise, the fresh granite dumps left on the hillside and the scars left by the excavation at the tunnel portals. Experiments were made by spraying oil with various chemicals on exposed rock cuts to create a stain that would blend with the natural rock and rockfalls of the surrounding topography. The color was too "warm" or brownish when bituminous spray was used, and time required for a slow, natural darkening of the granite by lichens was too long when oil alone was used. The idea of staining may have been influenced by the successful artificial coloration of concrete on the Ahwahnee Hotel and the staining of the new Suspension bridge across the Colorado River in Grand Canyon. Olmsted analyzed the problem from a visual perspective. He wrote,
But at best such camouflaging of the whitish color of the newly fractured granite will not prevent the form of any large area (visible as a unit) of dumped back of "run-of-the-mine" rock from showing up under many conditions of changing light as conspicuously different from any natural feature of the Valley. So far as it can possibly be accomplished, any definite interruption of visible continuity and uniformity, reducing the scale of what is recognizable by the eye as a single continuous unit of dump, is even more important than a general toning down of color contrast. [50]
Lampblack and oil was finally found to give the desired effect, and in the 1930s, the Wawona Camp of the Civilian Conservation Corps used spray guns to apply this to the exposed rock cuts along the roads and around the tunnel portals.
WESTCHESTER COUNTY PARKS EXCHANGE
The National Park Service collaborated with Gilmore Clarke as early as 1929, when he consulted on a new plan for Mammoth Hot Springs. This collaboration continued through an exchange of personnel for several summers between the Landscape Division and the Westchester County Park System in New York. Highly regarded by the landscape architecture profession, Clarke's work in Westchester County would have continuing influence, as would Clarke himself, who was involved in the construction of the George Washington Memorial Parkway and was a member of the Commission of Fine Arts in the 1930s. Wilbur Simonson, who directed the work on the George Washington parkway, and Stanley Abbott, who became the designer of the Blue Ridge Parkway, both worked under Clarke in Westchester County. Abbott brought the latest aesthetic and engineering principles to national park work and went on to create a scenic parkway innovative in the use of spiral transitional curves and its sequence of views of the rolling hillsides, farmlands, and forests.
In the winter of 1930 to 1931, John Wosky and Kenneth McCarter, assistant landscape architects on Vint's staff, spent two and a half months at Westchester County parks. There they studied the methods of highway design that had been developed by the Westchester County Park Commission and the operations of the commission and organization of the county park system. On their return trip to San Francisco, they were to visit the National Capital Park and Planning Commission to observe its planning process and to observe the development of the Mount Vernon Boulevard and Potomac Parkway, portions of which are now called the George Washington Memorial Parkway. In exchange, Clarke sent his assistant, Allyn R. Jennings, to the field office in San Francisco. Although a similar exchange was planned for the following year, in which Vint was to send either V. R. Ludgate from the Eastern Office or Davidson to New York, it's unclear whether the exchange actually took place. [51]
Park roads took on new direction in the 1930s with the development of the Colonial Parkway between Jamestown and Yorktown, the construction of the Mount Vernon Parkway (1930), Skyline Drive (1930), and finally the Blue Ridge Parkway (1935). These roads represent the fusion of the Landscape Division's experience in designing the roads of national parks in the West, the advances made by Westchester County under Clarke's direction, and the National Park Service's expanding definition of recreation. [52]
THE SIGNIFICANT LANDSCAPE DESIGN OF NATIONAL PARK ROADS
By 1929, the road and trail program was energetically being carried out under an appropriation of $5 million a year. A ten-year program was under way calling for the reconstruction of existing roads to modern standards, the construction of new roads, and the improvement and extension of trail systems. At the end of 1931, the National Park Service considered several of its road projects "outstanding." These were the Wawona Road and Tunnel in Yosemite, General's Highway joining Sequoia and General Grant parks, Trail Ridge Road in Rocky Mountain National Park, Rim Drive encircling Crater Lake, Going-to-the-Sun Highway in Glacier, Colonial Parkway between Yorktown and Jamestown in Virginia, and Skyline Drive along the crest of the Blue Ridge in the proposed Shenandoah park. In 1932, the first part (central) of Skyline Drive in Shenandoah had been graded, the Wawona Tunnel completed, and construction for the road from the Chinquapin Intersection to Glacier Point begun. In 1933, both the Wawona Tunnel and the Going-to-the-Sun Highway were dedicated. [53]
Viewing the role of the Landscape Division as central to the conservation of national parks, Secretary of the Interior Ray Lyman Wilbur remarked in 1929,
Preservation of primitive landscape conditions, adequate protection of wild life, and the safeguarding of forests and watersheds can not be carried out if a reasonable balance between accessibility and wilderness values is not maintained. A group of landscape architects pass on all plans for improvements in the park system and roads and trails are built to designs that will give least injury to natural features. [54]
By the end of 1930, the results of the division's efforts to protect the roadside and natural landscape were visible. Vint credited this to the accumulation of completed work of several years of road construction, the success of the new specifications from both aesthetic and economical standpoints, and the enforcement of type B excavation practices. He reported, "The results accomplished were the real test, yet it is noteworthy that their acceptance, by engineers and contractors was accomplished with little effort. Further, the bid prices were not as high as expected and, finally they have made for a proper understanding of what is desired." [55]
Director Horace Albright praised the progress made by the roads and trails program:
1930 is important in the annals of this division as the year in which the fruits of its labors to protect the roadside and the natural landscape generally during road and trail construction became definitely apparent, to the casual visitor as well as to the specialist. There is now a distinct contrast between carefully planned park roads and others planned on a strictly engineering basis. The cooperation of the road engineers aided greatly in achieving this result. [56]
By 1931, the division was providing architectural sheets for bridges, parking areas, intersections, and overlooks to the Bureau of Public Roads. Specifications covered such points as the rounding and flattening of slopes, removal of form marks, and methods of blasting less injurious to the surroundings. Quarries, borrow pits, and abandoned contractor's camps were left in a condition that could be naturalized. Embankments necessary to keep boulders, soil, and rubble from falling upon the roads or to reinforce a substantial area of fill to carry a road or support an overlook were being built by hand by dry-laid methods without mortar.
Recognition and praise also came from the Bureau of Public Roads. At the Twelfth Conference of National Park Executives, in 1932, Dr. L. l. Hewes, the deputy chief engineer of the Bureau of Public Roads, estimated that the bureau had built about $25 million worth of roads in the West for the service. He called the National Park Service's Landscape Division "pioneers" in road landscape work and urged the park service to expand the planting program. He stated,
When the history of this period is written, we are going to have to admit that the beautification of highways started as an offspring of this marriage of the Bureau of Public Roads to the National Park Service. Pennsylvania and Massachusetts have done conscious landscaping; that has been mostly planting. I think the Park Service could do more planting. I think the planting along the slopes could come out of the road funds.... It is a wonder to me they find so many different ways of giving the landscape effect because they are strictly limited; their manner of expression is very narrow. . . . The way to landscape a highway hasn't yet been found and there are no books about it, so this landscape division in the Park Service is doing pioneer work and we are learning with them and perhaps [they are) learning a little about roads from us. [57]
The achievements of the road-building program evolved from the technical and aesthetic experiments of the 1920s, the collaboration of the landscape architects and civil engineers, and the adoption of specific principles of design and practices of construction that emerged from Vint's office in the years from 1928 to 1932. Improvements continued during the 1930s, building upon the lessons of the 1920s and the groundwork of Vint's staff in the late 1920s. Road building in national parks was funded on a scale never-before imagined. Through public works allotments and the efforts of the Civilian Conservation Corps, the construction of roads and the finishing of slopes to a naturalized condition created efficient, safe, and naturalistic systems of roads in each national park and many monuments. The achievements of the roads program were seen primarily in the parks of the West before 1932. In the 1930s, the focus shifted to the parks of the East, where the park service assumed leadership in the development of scenic and historic parkways, thus realizing portions of Mather's vision for a park-to-park highway system. The early lessons and the advances worked out in the 1920s and 1930s continued to guide park road development. They were inherent in the intent, principles, and philosophy underlying the design standards for modern park roads that the National Park Service published in 1968.
The road program, perhaps more than any other aspect of national park development, endeavored to merge the disparate missions of the National Park Service—to make the parks accessible to the public while leaving them unimpaired for future generations. Recognizing the power of illusion inherent in the principles and practices of naturalistic landscape design in 1939, Henry Hubbard remarked on the success of the National Park Service's roads saying, "How much effort has been bent [sic] toward preserving the scene that they represent the effect that man has done nothing." [58]
The developments of park road construction would have lasting effects on the history of road building in America. In 1963, Christopher Tunnard, in Man-Made America, recognized the contributions of the National Park Service work to the development of the modern highway. He quoted the 1944 report of the National Interregional Highway Committee:
Flattened slopes of excavation and embankment and well-rounded cross-sectional contour are essential to prevent soil erosion and to minimize the risks of injury and damage when vehicles accidently . . . leave the roadway. They are needful also to mold the highway into the terrain and to make it a harmonious feature of the natural landscape. The flattened side-slopes will favor the growth of vegetation . . . and remove the cause of much troublesome clogging of the drainage system. The easier slopes can be removed by machine . . . and the streamline contours of cut banks will reduce snow-drifting and facilitate machine methods of snow removal. Design for utility and economy is found to go hand in hand with sound landscape design. [59]
Certain characteristics that the park designers had worked out and adopted proved valuable. The slopes of roads blended naturally with the space of the surrounding topography, when they were flattened in a ratio of 1:3 or even, if possible, 1:4. Cut or filled slopes were rounded and the edges warped. Tunnard listed the "lessons" which the highway designer can learn from the English garden landscape: "casual continuity, sensitivity to land form, skillful use of existing objects architectural as well as natural." Above all, he said, asymmetry was important. [60]
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