Design and Construction of Circuit Roads

<< Previous | Table of Contents | Next >>

Designing a new "Rim Drive"

On the most basic, functional level, there are several main reasons as to why the NPS and BPR undertook reconstruction of the Rim Road. The reasons addressed ameliorating a narrow, rough, dusty road with sharp curves and steep grades. Significant increases in visitation during the 1920s brought more traffic to the park, though at least one observer noticed that the existing road was so difficult to traverse that only a small proportion of motorists attempted to go around the lake.

View to the north of Wizard Island Overlook, with clouds obscuring the top of Watchman.

The NPS wanted the new Rim Drive to be a more pleasant visitor experience, but wanted to avoid creating a super-highway on which motorists "would speed around the lake and pass by scenes of beauty in their rush to make the lake circuit." BPR engineers thereby aimed for a constant average design speed of 35 miles per hour that would avoid gear-shifting on ascent or braking on descent. Instead of the switchbacks and short radial curves evident in places along the old road, designers preferred curvilinear alignment that allowed vehicles to maintain the design speed despite curves and changes in grade. These alignments allowed for constantly changing views by making use of continuous (also called reversing) curves instead of long straight sections (tangents), and eliminated the need for cuts and fills that would be both unsightly and expensive.

Engineers who located the first Rim Road attempted to provide viewpoints of the lake in as many places as possible. The location diminished the interest inherent in being routed away from the lake in some sections, as well as the excitement experienced by visitors in reaching certain viewpoints by trail. The road also created some scarring evident from a few places on the rim since the Army Corps of Engineers had virtually no funding to address landscape concerns, even if such expertise had been available. Designers of Rim Drive aimed for visual unity in reconstructing the road, which included removing it from what visitors saw from the main focal points, or vistas. Unity encompassed the consolidation of park facilities and integrating trail location and design with that of the road.

Another rationale behind reconstructing the Rim Road lay in providing an intended, rather than incidental, link between a road circuit presenting central features and its interpretation to visitors. John C. Merriam, who probably served as the leading figure in creating a formalized interpretive program at Crater Lake, remained adamant that the road primarily serve the purpose of "showing the great features" of the lake and its caldera. He thus decried any attempt to make it a link in a larger through route connecting various points and thought it best to avoid allowing any part of the Rim Road to become a segment of the park's approach roads. The circuit was instead be part of a plan aimed at presenting features of the region "determined by experts to be of outstanding importance." Merriam thought that Crater Lake offered "one of the greatest opportunities for teaching fundamental understanding of Nature."

With Crater Lake showing "the most extreme elements of beauty and power in contrast," the plan included the development of "stations" where certain views helped visitors appreciate "elements derived from the geological story of Crater Lake and those arising from elements of pictorial beauty." Merriam cautioned, however, that the "hand of the schoolmaster" not be overly evident at these particular places. The most overt attempt to educate visitors would instead be made at the Sinnott Memorial in Rim Village, a place Merriam referred to as "Observation Station No. 1." He saw it as the "main project," though "minor projects" of building the road, some trails, as well as additional observation stations had to be closely coordinated with developing the Sinnott Memorial for visitor orientation.

Where interpretation had formerly been incidental to the experience of traveling Rim Road during the 1920s, the slow metamorphosis of reconstruction was intended to bring this function to visitors in a more concrete way. Each of the seven observation stations built as part of Rim Drive were intended to serve as stops on the naturalist-led caravan that traversed the road in a clockwise fashion, from Rim Village to Sun Notch. All were chosen for their part in displaying a different aspect of the lake's beauty. Spaced proportionately around the lake, designers intended to each have hard-surfaced parking for a minimum of fifty cars.

Plans for each observation station were to match the "unique beauty of the lake itself," since Merriam thought the lake represented "a supreme opportunity to teach the significance of beauty through offering to the visitors the experience of beauty." The points chosen by Merriam and his associates on the western side of the rim were accessible by trail so that the road would not come near enough to the station to create "a disturbing element to one who wishes to observe the lake in quiet." This was something of a contrast with the four stations located on the northern or eastern side of the lake, which became part of the planning and design of the road. NPS landscape architect Francis G. Lange designated three of the four stations (Skell Head, Cloud Cap, and Kerr Notch) as "parking overlooks."

Merriam wanted a leaflet describing the stations of Rim Drive to be available at the Sinnott Memorial, in conjunction with adequate signs at each station. These stops might also include an inconspicuous holder for literature describing the station for those who did not visit Rim Village first. As a designer, Lange supplied a more detailed vision for the stations adjoining the road. They should contain, in his words,

"a small promontory circulation point with the necessary stone guard rail (log, if found more suitable) and an interestingly treated sign distinguishing the point in question, as well as denoting any other unusual features. It is also suggested that a suitable mounted binocular glass be set up at each point where found desirable, being mounted on an appropriate stone base."

For those stations accessible by trail, Lange recommended "stone steps if necessary, then a small promontory platform, some treatment of guard rail, possibly a sign and then a binocular mounted on a stone base."

Beneath the observation stations in a hierarchy of developed viewpoints along Rim Drive lay the substations, numbering thirteen in 1934, but increased (at least in plans) to seventeen a year later. Substations shared many similarities with the observation stations in that they were chosen for aesthetic or educational reasons, but differed in that they did not function as stops on the caravan trip, nor were all of them formally developed with paved parking areas, signs, or masonry guard rail. Unlike the stations, they sometimes highlighted features situated away from Crater Lake and often focused on specific geological features.

Developed pull outs or "parking areas" served as the next level below the substations in the hierarchy. Although not chosen at random, these stopping points lacked the aesthetic values attributed to the observation stations and substations. Lange commented in 1938 about an effort to restrict the number of such points. Where "an interesting view of the Lake can be obtained," he wrote, an effort "has been made to provide accommodations." He also noted in the same report that where "excellent" views of the hinterland existed, several small parking areas were provided.

Preserving the primitive "picture" of Crater Lake received greater emphasis from the engineers and landscape architects as they planned the reconstruction of Rim Road than the interpretation of beauty and geological features. Merriam stressed Crater Lake and its rim was one of the three most beautiful places in the world and that every effort should be made to keep the road from imposing on views of Crater Lake or the surrounding region. Landscape architect Merel Sager described how the greatest damage to park landscapes came from the construction of roads and urged that an "intelligent and comprehensive program of roadside development" could better fit these roads into their surroundings. This meant attention had to be paid to the road as seen in the landscape and the landscape as seen from the road.

Rim Drive followed the old Rim Road wherever possible to minimize impact. Landscape architects and the foremen under contract also paid special attention to planting the noticeable cuts in new sections and trying to disguise (or "obliterate") abandoned stretches of old road when funding allowed. Contract provisions called for protecting all trees not within the clearing limits (or "right of way"), placing dark soil and trees on conspicuous cuts and covering fills to diminish the ragged appearance of large rocks. Another dimension to the work involved "bank sloping," where flattening and rounding was aimed at stabilizing cut and fill slopes to permit establishment of vegetation, while warping aided the transition between the bank and roadway. All of these measures reflected the standard practice of using landscape treatments to contribute to the utility, simplicity, economy, and safety of scenic highways built primarily for the enjoyment of motorists. The national parks received special attention in this regard, partly because the NPS pioneered many of the standardized landscape treatments in road design.