In 1979, Montana Fish, Wildlife & Parks (FWP) adopted a new management focus for 

 Hebgen Reservoir based on a wild, self-sustaining fishery (Hetrick 1994). In pursuing 

 this objective, stocking practices shifted to using wild strains of rainbow trout (DeSmet 

 and Eagle Lake strains) and Yellowstone cutthroat trout (O. clarki boiiveri) in hopes of 

 enhancing spawning runs and recruitment to the fishery (Hetrick 1994). However, 

 reducing or eliminating stocking without understanding the contribution hatchery 

 rainbow trout provide to the fishery could have undesirable impacts on fishing success 

 and create controversy. 



The relative contribution of wild versus hatchery-reared rainbow trout to the Hebgen 

 Reservoir fishery and creel has been difficult to assess. Oswald et al. (1990) reported that 

 a "stocking check" was apparent on scales from fishes of hatchery origin. On that basis, 

 Oswald et al. (1990) estimated that 69% of rainbow trout sampled in Fall 1989 on 

 Hebgen Reservoir were of hatchery origin. Fredenburg ( 1 99 1 ) investigated spawning 

 runs in tributaries of Hebgen Reservoir and estimated that 590,000 rainbow trout fry 

 emigrated to the reservoir from its tributaries. Since 1990, gill netting has been the 

 predominant sampling method to determine relative abundance of the rainbow trout 

 population in Hebgen Reservoir. Hetrick (1994) reported a relationship between the 

 number and strain of rainbow trout planted with gill net catch as well as angler 

 satisfaction. However, gill net catches have varied considerably since 1994 in spite of 

 consistent stocking rates (Byorth and Weiss 2002). 



The relationships between wild rainbow trout recruitment, hatchery supplementation and 

 angler success have not been established. To characterize the fishery and analyze relative 

 contribution of hatchery and wild rainbow trout to the creel, a comprehensive creel 

 survey was conducted from June 2000 to June 2001 . The objectives of the creel survey 

 were: 



1 . Estimate the amount of fishing pressure exerted at Hebgen Reservoir over a 

 twelve month period 



2. Calculate angler catch-per effort and harvest for each species in the fishery 



3. Document the size and age distribution of fish creeled by anglers 



4. Assess the relative contribution of hatchery-reared and wild rainbow trout creeled 

 by anglers and 



5. Characterize anglers fishing at Hebgen Reservoir. 



METHODS 



Fishing Pressure Estimates 



Fishing pressure was estimated via direct angler counts. Creel clerks counted boat 

 anglers, shore anglers, and non-motorized boats (including fioat tubes) and recorded 

 counts on a form (Appendix A). To be valid "instantaneous" counts, they were to be 

 completed within a one-hour period (Neuhold and Leu 1957). Counts were conducted on 

 randomly selected dates stratified in two-week periods (strata), beginning June 12, 2000 

 ending June 10, 2001 (Appendix B). In order to adequately sample Hebgen Reservoir, it 



