Seven Cambrian formations and two Ordovician formations, with a total thickness of 9,000 feet, crop out west of the Paris thrust fault and comprise the upper plate. Slices of three Ordovician formations, one Silurian formation, two Mississippian formations, and one formation each of Pennsylvanian and Permian age comprise the low plate. Mesozoic units are not present in the mapped area. Two Tertiary formations and unconsolidated Quaternary deposits are also present. The major structural feature is the Paris thrust fault which extends north-south throughout the area. It was active during the Laramide orogeny. This fault involved eastward movement and placed Cambrian over Ordovician and later Paleozoic strata. The oldest formation exposed in the upper plate is the Brigham Formation which generally rests on the Garden City Formation. All units of the lower plate have been severely distorted and displaced by folding, thrusting, and reverse faulting. Both horizontal compression and gravity sliding have been invoked to explain this deformation. Gravity sliding is favored by many geologists; however, an uplifted source area has not been identified. Later, gravity faulting produced the major topographic features of the area today, notably the Bear River Range and Bear Lake Valley. (76 pages)

Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file and four media files (media file 1.pdf, media file 2.pdf, media file 3.pdf, and media file 4.pdf) Title from title screen of research.pdf file (viewed on August 25, 2008) Vita. Includes bibliographical references.

The Sharp Mountain area is situated in the southern part of the Bear River Range in Utah. The geology of the Bear River Range to the north of this area, in Utah and Idaho, has been mapped; however, prior to this study little was known about the Sharp Mountain area. The purpose of this investigation are as follows: (1) to map and describe the geology of the area, and (2) to relate the stratigraphic and structural features of the Sharp Mountain area to those of the surrounding region.

The Monte Cristo area is a 7 1/2-minute quadrangle located in the southeastern. part of the Bear River Range, northern Utah. It is within the Middle Rocky Mountain province and is 10 miles east of the Basin and Range province. Previous to this investigation little was known about the detailed geology of the area except for a reconnaissance study and general geologic map of the Cache County part included in the Geologic Atlas of Utah, Cache County, published by Williams (1958). The purposes of this investigation were as follows: (1) to determine the formations present in the area and their relation to regional stratigraphy, (2) to determine the structure of the area and its relation to regional.structure, and (3). to produce a geologic map of the area (Plate 1).

The fracture-dominated Tony Grove alpine karst system in the Bear River Range in north-central Utah, has caves ranging from 5m deep, consisting of solution-enlarged single fractures, to the large, 374m deep, Main Drain Cave, characterized by a series of vertical drops and horizontal passages. The caves int he Tony Grove area are developed throughout the 510m thick Fish Haven and Laketown Dolomites. The Swan Peak Formation, consisting of orthoquartzite and shale, underlies the dolomites. Surface fracture measurements (n=3502) yielded two distinctive sets of fractures. The northeast-southwest sets had a mean orientation of 41±0.7° and the northwest-southeast set with a mean of 133±5°. Of the sixteen caves surveyed for fractures and passages, fifteen were controlled by fractures, although some caves had both facture-and non-fracture-controlled passages. Only one cave was entirely non-fracture controlled, likely due to a change in lithology. Main Drain Cave, the only cave with long horizontal passages, was surveyed for both fracture and stratigraphic influences on horizontal cave development. Results indicate some sections are controlled by southeast-trending-fractures and other sections are controlled by southwest-dipping-bedding planes. Alternatively, parts of the down-dip-oriented sections may be influenced by southwest-oriented fractures. Stratigraphic control in this cave includes cherty layers that appear to hinder down-cutting of passages into lower stratigraphic units. Surface mapping determined that there is a southeast-oriented fold pair east of the Logan Peak Syncline, consisting of the Naomi Peak Syncline and the Cottonwood Canyon Anticline. The anticline merges with the Logan Peak Syncline near the head of Cottonwood Canyon. The Naomi Peak Syncline continues north-northeast through the Tony Grove area and may divert water from the Tony Grove area to Wood Camp Hollow Spring in Logan Canyon. The anticline acts as a divide between groundwater traveling southwest to Dewitt Spring and south-southeast to Wood Camp Hollow Spring. The Swan Peak Formation appears to act as a barrier to groundwater movement into the underlying formations, separating the Tony Grove system from underlying systems.

The structure of the western three or four miles of the Bear River range east of Logan, Utah, has many times been alluded to in papers written locally on Cache Valley and the related ranges. There has not however, ever been, to the author's knowledge, an investigation made of this portion of the range for the express purpose of determining its exact structure. Although the area specifically covered by this present investigation is greatly inadequate to base the whole west range structure on, the author believes that the facts brought to light by the specific study of this area, added to the facts already known of the rest of the range, will give a clearer and more comprehensive interpretation of the whole western Bear River range front. It was with this purpose in mind that the present investigation was made. The original outline for the study included an investigation of the paleontology of the section. It was found however, after a few weeks study in the field, that the fossils in the local section are far too scarce for any comprehensive study in the present investigation. The study herein described then will be found to refer to paleontology only where it is necessary or where fossil horizons were found advantageous over lithologic units for mapping of formations. The section represented here has several times been studied in part. With a study of these investigations, it was found that there was enough lithologic difference in most of the sections to make possible local correlation and mapping on that basis. In order to make the present paper more thorough and complete it seemed advisable to branch out from the specific area in a few cases and investigate other parts of the valley and range for further insight.into some of the problems confronted on the area. It was also found necessary to make a rather complete study of the literature of related areas.

In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing habitat, thereby threatening their long-term local and regional viability. Though lichens have a rich history as air pollution indicators, I believe that they may also be useful as a metric of community diversity associated with habitat change. To date, few studies have specifically examined the status of aspen's epiphytic lichen community in the Rocky Mountains. A preliminary study was conducted using 10 transect-based plots to assess lichen species substrate preferences between aspen and various conifer species and to gain basic knowledge of species diversity. Following this work, I established 47 plots in the Bear River Range of northern Utah and southern Idaho to evaluate the effects of forest succession on epiphytic macrolichen communities. Plots were located in a narrow elevational belt (2,134-2,438 m) to minimize the known covariant effects of elevation and moisture on lichen communities. Results show increasing lichen diversity and a decrease in aspen-dependent species as aspen forests succeed to conifer cover types. The interactive roles of stand aspect, basal area and cover of dominant trees, stand age, aspen bark scars, and recent tree damage were examined in relation to these trends. An aspen index score was developed based on lichens showing an affinity for aspen habitat. I present a landscape-level multivariate analysis of short and long-term factors influencing epiphytic lichen communities in aspen forests. Nonrnetric multidimensional scaling (NMS) ordination stressed the importance of succession and local air pollution sources in shaping lichen communities. I also investigated the role of historic human intrusions and climate on aspen forests and aspen dependent epiphytic lichens at the landscape-level. Implications of this work include 1) realization of nitrogen impacts on ecosystems, 2) the potential for using lichens as bioindicators for monitoring aspen stand health, and 3) suggestions for working with natural disturbance regimes to minimize human impacts on aspen and associated species.

A study of the spring and summer habitat preferences of blue grouse was conducted on the Bear River Range in northern Utah. The main objective was to determine the important factors associated with habitat selection by blue grouse during the breeding season. One hundred and two sampling areas, delimited by similarities in vegetation and topography, were thoroughly searched with a dog for blue grouse. Fifty-four bio logical and physical variables were measured for each sampling area. Chi-square tests performed on all variables showed 11 of the 54 variables to be significant at an alpha of 0.20. These 11 variables (li sted below) were considered to be the important factors influencing habitat selection by blue grouse. (1) search area type (2) area exposure (3) elevation (4) percent forested (5) understory density (6) primary cover species (7) secondary cover species (8) percent cover maples (Acer grandidentatum) (9) percent cover mixed brush (10) percent cover sagebrush (Artemisia tridentata) (11) total acres The chi-square test only determined if a variable significantly effected habitat selection by blue grouse. To determine whether this effect was positive or negative, the percent occurrence of areas on which blue grouse were present, or absent, was determined. Results indicated that the most favorable blue grouse habitat was draws at 5,500 -6.499 feet elevation. This favorable habitat contained 1-10 percent cover by maples, or a higher percent of maple which provided a large amount of edge effect; the presence of mixed brush or sagebrush, a medium understory, and an area incline of 5-19 percent.

The study of environmental history suggests that nature and culture change all the time, but that the rate and scale of such change can vary enormously. During the late 19th and early 20th centuries, Anglo settlement in the American West transformed landscapes and ecologies, creating new and complex environmental problems. This transformation was particularly impressive in Cache Valley, Utah's Bear River Range. From 1860 to 1910, Mormon settlers overused or misused the Bear River Range's lumber, grazing forage, wild game, and water resources and introduced invasive plant and animal species throughout the area. By the turn of the 20th century, broad overuse of natural resources caused rivers originating in the Bear River Range to decline. To address the water shortage, a small group of conservation-minded intellectuals and businessmen in Cache Valley persuaded local stockmen and farmers to support the creation of the Logan Forest Reserve in 1903. From 1903 to1910, forest managers and forest users attempted to restore the utility of the landscape (i.e., bring back forage and improve watershed conditions) however, they quickly discovered that the landscape had changed too much; nature would not cooperate with their human-imposed restoration timelines and desires for greater profit margins. Keeping in mind the impressive rate and scale of environmental decline, this thesis tells the heretofore untold environmental history of the Bear River Range from 1860 to 1910. It engages this history from an ecological and social perspective by (1) exploring how Mormon settlers altered the landscape ecology of the Bear River Range and (2) discussing the reasons why forest managers and forest users failed to quickly restore profitability to the mountain landscape from 1903-1910. As its value, a study of the Bear River Range offers an intimate case study of environmental decline and attempted restoration in the western United States, and is a reminder of how sensitive our mountain ranges really are.

Quaternary basalts of Gem Valley, Idaho, are present as valley fill (Group 1) and as well defined flows in the Bear River Range (Group 2) east of Gem Valley. Minerals present in both groups of basalts include olivine (Fo73 -Fo39), augite (Wo41 En39 Fs20), plagioclase (An75 -An40), and Fe-Ti oxides. Coexisting pairs of magnetite and ilmenite, and olivine and clinopyroxene in several samples indicate temperatures of crystallization from 958°c to 1167°c. The Group 2 basalts exhibit a cumulate texture with abundant large (2 cm) phenocrysts of plagioclase. Chemically, the Gem Valley basalts are similar to the basalts of the Snake River Plain with respect to SiO2, total Fe, P2O5 and Na2O but differ in the amounts of Al2O3 and MgO present. The Al2O3 is generally higher and the MgO is generally lower in the Gem Valley basalts. Comparing Group 1 with Group 2 basalts, the Group 2 basalts generally have more alumina and alkalis than the Group 1 basalts. Chemically both groups of basalt exhibit characteristics of the tholeiitic basalt suite, because they are hypersthene normative. Mineralogically, both groups of basalt contain but one pyroxene, augite, which is characteristic of the alkali-olivine basalt suite. This apparent contrast in classifications may be resolved by referring to these basalts as transitional between the alkali-olivine and tholeiitic basalt .suites, with the restriction that no genetic relationship to either suite is implied. Within the limits of this study, it is proposed that the Group 1 basalts may have formed by the partial melting of mantle material with a pyrolite composition. Furthermore, the Group 2 basalts appear to have originated as a result of the accumulation of plagioclase in a fractionating magma of Group 1 composition.