We evaluated Wyoming Game and Fish Department (WGFD) file information to determine the species of trout raised, the number of catchable-and subcatchable-size trout stocked, the return rate of stocked fish to the creel, reasons for variability of return rates, and the direct cost associated with stocking trout. About 8.9 million trout were planted yearly from 11 WGFD hatcheries during 1987-1990; 86% were of subcatchable size (<8.25 in) and the rest were of catchable size (^8.25 in). Rainbow trout Oncorhynchus mykiss and cutthroat trout O. clarki were most often stocked. Evaluation showed that return rates (percent of number planted that were caught) to anglers were usually greater for catchable than for subcatchable fish. Catchable trout should be stocked in spring and when fishing pressure is highest for best returns; few catchable trout planted after the fishing season survive to the next season. Return rates of subcatchable trout planted in streams varied due to differences in water quality in the hatchery and receiving water, poststocking competition with other fish, time of stocking, and size of fish stocked. Subcatchable trout should be stocked in streams in spring and only when hatchery and receiving water are of similar quality, water temperature and flows are not limiting, and few competing fish are present. Higher returns in streams also occur as larger fish are stocked. Return rates of subcatchable trout were greater for lakes than for streams. For highest lake returns, subcatchable trout should be stocked in productive waters (indicated by total dissolved solids) where competing planktivores and piscivores that prey on stocked trout are few. The cost of production and distribution was US$0.68/fish for catchable and $0.13/fish for subcatchable trout. Mean cost offish reaching the creel was less for catchable trout (lakes, $2.32; streams, $3.67; 1953-1989) than for subcatchable trout (lakes, $37.44; streams, $6.29; 1953-1988). Research opportunities include developing foresighted management plans based on a combination of biological technology and public desire, evaluating the elimination of subcatchable plantings in streams and alternative management for wild trout, evaluating the transplantation of wild trout or eyed eggs of wild fish as a means of establishing fisheries, evaluating stocking guidelines applicable to various Wyoming conditions, determining the effect on harvest of behavioral differences between hatchery and wild trout, and comparing the genetic backgrounds of hatchery trout to determine their effects on postplanting survival.Anglers in Wyoming believe both that planting in southeastern Wyoming was high because drainhatchery-reared trout is valuable for maintaining ages such as the North Platte River had no native good fishing and that wild trout are important, and trout. More recently, the Wyoming Game and Fish they have a wide variety of perceptions about fish-Department (WGFD) has used hatchery trout to ing (Anderson et al. 1990). Production of hatchery replace wild stocks lost throug...

An average of 8.9 million trout (Oncorhynchus spp., Salmo trutta, Salvelinus spp.) were planted in Wyoming each year from 1987 through 1990; 86% were of subcalchable size (<8.25 in) and 14% were of catchable size (>8.25 in). Of the total fish planted, 1.9 million subcatchable trout and 177,000 catchable trout were planted in streams. Harvest rates of trout stocked in streams was low (average, 5.7%), possibly because of the hatchery conditions under which they were reared. Hatchery-reared trout were raised in conditions far different from those of natural waters: densities hundreds of times those in the wild, nearly constant water flow and water temperature, regular feeding, lack of cover, and absence of predators. Hatchery trout may become disoriented, fail to seek cover, forage inefficiently, and die when planted in streams with competing fish. Evaluating the survival of hatchery trout fed natural food, rearing hatchery trout in simulated natural conditions, raising them at moderate densities, and evaluating costs associated with management of wild and hatchery trout would provide additional means for judging the potential to train hatchery trout to survive in the wild. Such evaluations also would provide more criteria upon which to judge the success of planting hatchery trout.