The Battle Against Bark Beetles in Crater Lake National Park: 1925-34
The tide of the control battle has ebbed and flowed. The control forces have given the enemy repeated setbacks, but until recently the beetles on the southern front have had their forces strengthened by reinforcements from the north. The northern reserves are now depleted, and the remnants of the beetle army are widely dispersed and rendered ineffective with only a few concentrated groups operating in territory outside the former battlefields. The ultimate victory is now in sight. 
If this sounds like war, it was. The protection of the lodgepole pine (Pinus contorta Dougl. ex Loud.) forests of Crater Lake National Park from destruction by the mountain pine beetle (Dendroctonus ponderosae) has engaged the attention of the National Park Service and the U.S. Department of Agriculture, Forest Service and Bureau of Entomology, since 1925, and despite Entomologist F.P. Keen’s optimism in 1930, the war was far from over.
Let us go back a few years and see how this quasi-war of man against beetles began and why so much effort and money was expended to win the “ultimate victory.” In 1923, the Superintendent of Crater Lake National Park requested help from the Bureau of Entomology because groups of lodgepole pine in the northern portion of the park were being killed by the mountain pine beetle. Because the dominant tree within the park was lodgepole pine, Park Superintendent Colonel C.G. Thomson visualized the park would become a “windblown, sandy desert without the lodgepole pines.”  During that summer, John E. Patterson responded for the Bureau from its Ashland, Oregon, field station and made a first examination of the outbreak. Because the Park Service had no funding for insect control in 1924, plans were made to do a more extensive survey in summer 1924 and to request funds to start control operations in 1925.
The epidemic apparently started 10 years earlier in National Forest stands northeast of the park near Diamond Lake and spread slowly southward killing from 50 to 90 percent of the stand as it progressed.