Cougars (Puma concolor) are elusive top-level predators and their predation patterns, particularly upon sensitive species, can be a source of concern to wildlife managers. Predation patterns, however, vary widely in accordance with differing landscape attributes, prey community composition, and preferences of individual cougars. The objective of this study was to better understand the impact of cougars upon their prey in the Pryor Mountains of Wyoming and Montana. Managers were concerned that cougar predation was having a negative impact upon a small, isolated Rocky Mountain bighorn sheep (Ovis canadensis canadensis) population and were hoping predation might be limiting a burgeoning feral horse population (Equus caballus). With GPS collar data, we examined cougar kills (n = 200) to determine kill rates, prey composition, and selection for prey. Our findings indicated this population of cougars preyed primarily on mule deer (Odocoileus hemionus; 71.5%) but also included a substantial amount of bighorn sheep (8.0%) and other prey items (19.5%) in their diet. All bighorn kills were attributable to a specialist individual and we found no evidence of predation upon feral horses. Results showed that, while cougar predation was not limiting the feral horse population, at times, predation could be one of a host of factors limiting the bighorn sheep population. To better understand the link between the risk of cougar predation and landscape attributes, we examined predation-specific resource selection by cougars. We first compared our set of confirmed kill sites to random sites at a fine scale (within 25 m of kill sites). We then built resource selection functions to conduct a coarse-scale analysis by using the 95% upper cut-off point of the known distances-dragged (94.9 m) to buffer caches sites, thereby creating zones of risk which had high probabilities of containing kill sites. We found that risk of cougar predation was associated with vegetation class and increased with decreasing horizontal visibility. For bighorn sheep, risk of predation was associated with juniper-mountain mahogany (Juniperus spp., Cercocarpus ledifolius) woodlands. We recommend managers thin junipers to increase horizontal visibility in areas where the juniper-mountain mahogany vegetation class intersects bighorn sheep habitat.

Twenty- six sedge-dominated sites in the Uinta Mountains of northeastern Utah were studied. These sites could be placed into two categories, wetland sites (those with water-saturated soils) and alpine tundra sites. The alpine sites had above-ground standing crops between 37 and 206 g/m2 • The soils were sandy and low in nutrients. Indirect gradient analysis of the alpine sites showed a relationship between soil stability and vegetation. No other factors were found to be related to overall vegetation patterns. The wetland sites were dominated by different Carex species than the alpine sites. These wetlands were often patches of monotypic stands. Above- ground standing crop values ranged from 28 360 g/m2 and were strongly dependent upon the stagnation of the water on the site.

The High Uinta Primitive Area, Utah's most popular high mountain recreation area, has a reputation as an excellent trout and grayling fishery. Proposed for inclusion in the National Wilderness Preservation System, the area faces several management dilemmas. The primary problem being that managers must protect the resource from the effects of heavy recreational use without destroying the primitive and aesthetic dimensions of wilderness environment. It appears that much impact on the more accessible lakes is due to fishing use. The objectives of the study were: (1) to determine the proportions of angling to non-angling groups; (2) to describe certain characteristics of these anglers; (3) to examine the importance of fishing and factors affecting fishing enjoyment; and (4) to determine the angler's knowledge and experience with adjacent de facto wilderness alternatives. The method of data collection was an interview questionnaire administered on Highline trail leading into the Primitive area and Notch Mountain trail leading to de facto wildlands. A conservative stratified sampling scheme was used to obtain proper representation of weekday, weekend and holiday users of both areas. Results were coded and punched for computer organization and tabulation. The results indicate that slightly more than half the groups contacted were comprised of one or more fishermen planning to fish the study area; with slightly greater proportions of anglers using the Primitive area. Over half the anglers were visiting the areas for the first time and were motivated by the desire to "escape" from routine, get outdoors, and enjoy mountain scenery. Fishing was not an important motive but was a preferred activity. Anglers of the study areas fished more than average Utah fishermen and preferred high mountain lake and stream fisheries. Anglers reported high catch rates and mostly rated the fishing as "good" . Hypothetical catch reductions did not bother anglers because as many stated , "fishing was secondary". However, the dissatisfactions of less successful anglers and the angler's desire to maintain the fishery through stocking still reveal some importance in fishing activity. Anglers also appeared to be somewhat intolerant with increased crowd levels. Most anglers were inexperienced and ignorant of de facto alternatives. It appeared that decisions regarding such alternatives were partially based on Notch Mountain standards. Also, the accessibility and high amounts of dayuse suggest that different kinds of experiences may be sought in the Notch Mountain area.

The purpose of this study is to characterize the metasomatism that has taken place as a result of the chemical incompatibility between mafic and metaultramafic bulk compositions during high-grade regional metamorphism in the Tobacco Root Mountains, southwest Montana. Metasomatism of these rocks took place by both diffusionand infiltration-dominated processes. The result of these processes are characterized mineralogically and geochemically in the rocks.

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That tornadoes cannot occur in mountains due to disruptive influences of the complex terrain is a common misperception. Multiple tornadoes occur each year in mountainous environments, including the Appalachian Mountains. Copious research examines the influences of complex terrain on large severe weather systems such as multicell convective systems and squall lines, but research is lacking investigating this same relationship for smaller-scale severe weather phenomena like supercells and tornadoes. This study examines how complex terrain may have influenced the rotational low-level wind fields of fourteen supercell thunderstorms in the Appalachians. The terrain variables include elevation, land cover, slope, and aspect. Using GIS mapping techniques, the individual storm tracks were overlaid onto elevation, land cover, slope, and aspect layers; points along the storm tracks were measured to correlate storm intensities with the underlying terrain. Hypotheses predict that lower elevations, areas of shallower slopes, agricultural land covers, and terrain features with a southeasterly orientation represent terrain variables that would enhance low-level rotation in the lower levels. Results indicate that elevation has a significant impact on storm rotational intensity, especially in mountainous regions. Lower and flatter elevations augment storm rotational intensity, and higher elevations decrease storm rotational intensity. Additionally, northern and western facing slopes exhibited a negative relationship to storm intensity. A qualitative examination revealed vorticity stretching to be evident in eight of the fourteen storms; with vorticity stretching evident on both southeasterly and northwesterly slopes. Future research on appropriate scale for storm-terrain interactions could reveal even stronger relationships between topography and supercell thunderstorms. / Master of Science

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Accompanied by 3 folded plates in envelope inserted in back cover. / Bibliography: leaves 165-170. / by Gary James Axen. / M.S.