History of Rim Drive, Crater Lake National Park
Design and Construction of Circuit Roads
The Need for Reconstruction
The National Park Service assumed control of the roads in Crater Lake National Park once the engineers departed, but available funding allowed crews to open the circuit each summer by hand shoveling, followed several weeks later by horse drawn equipment that removed rocks from the roadway. By 1923 Park Superintendent C.G. Thomson lamented to NPS director Stephen T. Mather that a rising number of vehicles made maintenance difficult in the absence of surfacing material, since the annual re-grading each fall could not adequately alleviate the problems associated with a rough dirt road. Publicly, however, Thomson extolled the numerous wonders seen from the Rim Road in promoting the park to visitors. According to him, the circuit should be seen as “not a joy ride, but a pilgrimage for the devotees of Nature.” It was where “a hundred views of the magic blue lake and its huge shattered frame” highlighted the “thirty four miles of amazing beauty, three hours of vivid and changeful panorama.” He knew what 200 cars per day over the course of nine weeks each summer could do to such an earth graded road, but Thomson counseled prospective visitors to “approach the experience [of driving around the rim] in a leisurely and appreciative mood, and great will be your reward.”
No matter how reverent the motorist, few considered the Rim Road to be adequately constructed as passenger cars became heavier and faster during the 1920s. Within a decade of the circuit’s “completion” by steam shovel and horse-drawn grading equipment, the narrow roadway made passage of vehicles headed in opposite directions difficult. Even though the average radius of curves “greatly exceeded” 100′, with none being less than 50′, they seemed tight by the highway standards of 1926. Curves needed to be lengthened so drivers could better sustain the posted speed throughout their journey around the rim. Grades varied from 2 to 8 percent (with some stretches of road at 10 percent for short distances), representing another design problem at a time when engineers agreed that a 5 percent grade should be the maximum allowed.
Metamorphosis of the Rim Road into a new circuit of Crater Lake took place as the state highway system and forest roads around the park experienced both steady and dramatic changes spurred by an infusion of federal highway funds expended through the Bureau of Public Roads (BPR). The road system in Oregon grew with the help of funds authorized by the congressional acts of 1916 and 1925 that were aimed at providing the states with aid in building highways. The BPR subsequently supervised contracts to upgrade approach roads to the park, such as the Crater Lake Highway (numbered as 62 after 1926), which had been part of the state system beginning in 1917. It also took the lead in the improvement of the federal system of roads, such as U.S. 97 (also known as The Dalles — California Highway) that served as the main north-south corridor through central Oregon, one that ran just east of the park.
Throughout the 1920s and 1930s, several roads built in the national forests near Crater Lake became part of the state highway system, including one connecting Union Creek with the south shore of Diamond Lake, and then over to U.S. 97. The most profound effect on the park visitation from building new roads, however, came in 1940. Realignment of U.S. 97 away from Sun Mountain and Fort Klamath dramatically reduced visitor traffic through the east entrance, but opening the Willamette Highway (numbered 58) from the north allowed park visitors to save about two hours over what had been the quickest route from Eugene. Previous work to provide a passable road through the park (much of it involved upgrading the Diamond Lake Auto Trail into the North Entrance Road) to a new “north entrance,” in concert with the effort to connect Diamond Lake with U.S. 97 played an important part in the park’s visitation reaching the unprecedented figure of 252,000 that year. At that point the western portion of the Rim Drive began to serve as both through route and a portion of the circuit road around Crater Lake.