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habitat and/or in adjacent, but interconnected sub-basins where metapopulation dis- persal occurs. Agencies need to work together to eliminate non-native threats within the sub-basin where they are occurring or could occur, while still maintaining historic biodiversity . 3. Where pure populations occur outside their historic range care should be taken to protect and preserve the populations. Management emphasis and conservation strate- gies should apply equally to these sub-basin ecosystems as they would to pure popula- tions within the Bonneville Basin. 4. Since few pure populations occur in stream-lake interchange environments, it would be beneficial to enhance certain sub-basin populations by introducing BCT into high- elevations historic occupied waters on national forests, particularly wilderness and roadless areas. Such extension of distribution could occur in the High Uinta Wilderness Area and Uinta Mountain Range. It could include introduction into historically fishless waters if necessary outside of wilderness area or into waters where non-native or exotic trout have been removed. This should only be done once it has been jointly determined by management agencies that such introduction would not place at risk or eliminate other indigenous aquatic communities and flora. It may further be necessary to protect these pure populations from upper watershed threats, if such exists at higher eleva- tions, by removing non-native or exotic fish, or by discontinuing stockings and allowing Jakes to revert to their historically fishless state. C} RESTORATION An important focus for agency emphasis is the restoration of BCT populations within their historic range. Because natural populations have collapsed throughout their range, we must identify methods that preserve the remaining genetic diversity, and at the same time increase the number of pure populations and expand their distribution within the Bonneville Basin. 1. Emphasis should be focused on restoration of genetically pure populations. Restora- tion of streams within the same sub-basin in which pure populations occur should be given priority. Genetically significant watersheds and sub-basins should be identified, since geographic isolation has resulted in significant genetic differences in populations within the subspecies' range. Pure populations should only be used within the same major sub-basin in which they occur, and re-introduced only into streams that have no exotic or introgressed populations. Management of and for supplemental gene flow must be practiced with caution so as not to lose unique genetic traits of individual populations within geographically separated or isolated sub-basins. If historical corri- dors for gene flow have been .recently. severed by anthropogenic factors, then the adverse effects of a loss of or reduction in genetic diversity in small, subdivided popula- tions could be reduced or reversed by small scale introductions among previously contiguous populations. For example, restoration of Western Bonneville (WB) popula- tions in the Snake Valley sub-basin should draw on existing WB population exchanges rather than mixing them with other similar, but geographically isolated populations (Le. Northern Bonneville populations on the east side of the basin). 2. Priority watersheds, within sub-basins, should be established and managed as a unit to serve as networks of refugia These watersheds should provide both excellent habitat and strong assemblages of indigenous species, as well as have a high restoration 55