The year 1946 marked a transition from war-time to peace-time operations which entailed many readjustments in forest protection at Crater Lake. During the year the ranger and fire protection forces handled only five forest fires, all inside the park, three of which were lightning-caused and two man-caused. The Fire Weather Unit of the U.S. Weather Bureau broadcast daily fire weather forecasts and supplemented these with telegraphic forecasts at particularly critical periods. Local fire weather conditions were determined by the stations at park headquarters and the Watchman Lookout. A revised administrative plan of action (Strength of Force Plan) was developed to ensure improved fire protection and suppression (a copy of the plan may be seen in Appendix A). Improvements were made to the Watchman and Mount Scott lookouts, the park telephone and radio communication systems, and the truck trail system for fire control purposes. [41]
During the fall of 1946 a field survey and report of mountain pine beetle infestation conditions by R.L. Furniss of the Portland Laboratory of the Bureau of Entomology and Plant Quarantine led to the development of an insect control project at Crater Lake. The project was carried out in May-June 1947 and had as its objective the halting of an aggressive beetle infestation in the lodgepole pine stands in the southeastern section of the park. Two treating methods were used–solar heat and lethal oil spray. Wherever possible the solar heat method was employed as it was quicker and less costly. Both methods required that the trees be felled, limbed, and the tops cut off. [42]
During the postwar years park management gave increasing attention to the question of recreational fishing at Crater Lake. While a definitive policy was not formulated, the park took the position of neither encouraging nor discouraging fishing pending further limnological studies. In August 1948 Superintendent Leavitt explained the rationale behind the park staff’s thinking on the subject:
. . . beginning with the season of 1937 a research project was started by conducting limnological studies by Professor A.D. Hasler under the supervision of former Park Naturalist John E. Doerr. The primary purpose was to determine the amount and character of fish food available in the lake to the rate of growth of fish, fishing conditions, and related data in order to obtain the information necessary in carrying out our fish planting and fish catching program. These studies have been carried out since that date from season to season under the general supervision of Dr. Donald S. Farner, interrupted, of course, by the war period and Dr. Farner s inability to be with us every season.
Our studies began on a theory that fish were unable to spawn in Crater Lake. We found this to be untrue as there is definite evidence that the silverside salmon do spawn in Crater Lake, and we have good reason to believe that the rainbow trout do also. If natural spawning occurs in the lake, the management program that we visualized at the beginning of our study cannot be carried out because of inability to control the number of fish that might be introduced into the lake through spawning. All our studies to date indicate that there is a great deal of information still to be obtained before we can determine whether we shall attempt to continue Crater Lake as a fishing lake as it has been in past years or whether we will let the fish die out and keep Crater Lake in a natural and unmodified condition without fish life as it was when first discovered.
More and more we are thinking seriously of endeavoring in every possible way to keep the waters of Crater Lake, the crater walls, and Wizard Island areas in as natural a condition as possible, unmodified by the hand of man.
There are many lakes in Oregon suitable for fishing, boating, swimming, and other recreational sports, but there is only one Crater Lake in the world. [43]
