described and recorded. Fishing has been 



opened on most lakes within the district on a 



year-round basis. Lake rehabilitation was 

 undertaken in two areas. 



During the summer of 1958 and the winter 

 of 1958-59 a detailed creel census was con- 

 ducted on Georgetown Lake. The purpose of 

 the study was to get good estimates of total 

 fish taken and the fishing effort exerted on this 

 popular lake. This census will be repeated at 

 two-year intervals for at least six years. Re- 

 sulting information will provide the basis for 

 maintaining the highest quality fishing possible 

 in Georgetown Lake. Estimates from the first 

 year's study showed that 25,000 fishermen 

 caught 47,000 game fish during the summer 

 season. During the winter season 18,000 ang- 

 lers took an additional 70,000 game fish. By 

 weight, these fish totaled 41 tons, or almost 

 thirty pounds of game fish per acre from this 

 productive mountain lake. 



Bob Averett, pollution control biologist, sets up field 

 equipment while working on a water problem. 



( Photo by Tom Smith- ) 



Two major pollution problems confronted 

 the western fisheries district during the past 

 biennium. Both were on the Clark Fork River 

 — one in 1958 from about 10 to 60 miles west 

 of Missoula, and the other in early 1960 from 

 the river's headwaters to an as yet unknown 

 distance downstream. Immediate investiga- 

 tion of both problems in cooperation with pol- 

 lution control authorities led to the immediate 

 discovery of pollution sources and their sub- 

 sequent abatement. Follow-up studies on the 

 1958 problem, associated with the pollution 

 control project, have provided estimates that 



game fish were removed from 25 miles of the 

 Clark Fork. An appraisal of recovery was also 

 established. A similar investigation of the 1960 

 problem area is scheduled. 



During early summer of 1959 the U. S. 

 Forest Service sprayed DDT for control of 

 spruce budworms in portions of the east and 

 west forks of the Bitterroot River and their 

 tributaries. In order to determine the effects 

 of this program upon aquatic life in the area, 

 a fishery study was conducted coincident with 

 the spray program. Insect and fish mortalities 

 that occurred during the spray job were in- 

 vestigated and the spray operation was closely 

 observed both from the ground and the air. A 

 report on this study is being prepared. 



A major, long-range rehabilitation project 

 on the Clearwater lakes was started during 

 the biennium. From September 10 to Novem- 

 ber 11, 1958, the upper Clearwater drainage 

 (Rainy, Summit and Clearwater Lakes and 

 their connecting streams) were treated with 

 fish toxicants. Two hundred and twenty-four 

 surface acres of lake water and nine miles of 

 stream were treated. The purpose of the job 

 was to improve trout fishing by removing 

 suckers, squawfish, chubs and yellow perch 

 and restocking the waters with cutthroat trout. 



The entire Clearwater Lake chain would 

 constitute too large and expensive a job for 

 the department to undertake all in one year. 

 Also, it is good business to evaluate the prob- 

 able effects of a project of this magnitude 

 before undertaking it in its entirety. Conse- 

 quently, the overall job will proceed slowly 

 by small sections of the drainage. A fish bar- 

 rier at the outlet of Rainy Lake prevents the 

 movement of rough fish into treated upper 

 areas. Through preliminary surveys in the 

 summer of 1959, a second possible barrier site 

 below the outlet of Inez Lake was located. 

 During the next biennium, a detailed barrier- 

 engineering survey, the construction of a bar- 

 rier below Inez Lake, the rehabilitation of 

 Alva and Inez portions of the drainage, and 

 an evaluation of the fishing provided in the 

 completed sections are scheduled. 



During the fall of 1959 Rock Creek Lake, 

 a small reservoir near Deer Lodge, was drawn 

 down from its normal 3.700 acre feet to 1.000 

 acre feet in order to repair the dam. This 

 offered an opportunity for chemical treatment 



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