Longitudinal profile , channel cross-section geometry, and depositional patterns of the Green River in its course through the eastern Uinta Mountains are each strongly influenced by river-level geology and tributary sediment delivery processes. We surveyed channel cross sections at 1-km intervals, mapped surficial geology , and measured size and characteristics of bed material in order to evaluate the geomorphic organization of the 70- km study reach . Canyon reaches that are of high gradient and narrow channel geometry are associated with the most resistant lithologies exposed at river level and the most frequent occurrences of tributary debris fans. Meandering reaches that are characterized by low gradient and wide channel geometry are associated with river-level lithology that is of moderate to low resistance and very low debris fan frequency. The channel is in contact with bedrock or talus along only 42 percent of the bank length in canyon reaches and there is an alluvial fill of at least 12 m that separates the channe l bed from bedrock at three borehole sites. The influence of lithology primarily operates through the presence of resistant boulders in debris fans that are delivered by debris flows from steep tributaries. The depositional settings created by debris fans consist of (1) channel-margin deposits in the backwater above the debris fan, (2) eddy bars in the zone of recirculating flow below the constriction, and (3) expansion gravel bars in the expansion below the zone of recirculating flow. These fan-eddy complexes are the storage location of about 70 percent, by area, of all fine- and coarse-grained alluvium contained within the canyons above the low-water stage. Immediately adjacent meandering reaches contain an order of magnitude more alluvium by area but have no debris fan-created depositional settings. This study also describes the flood-plain and terrace stratigraphy of the Green River in the eastern Uinta Mountains and changes due to the operations of Aarning Gorge Dam, upstream from the study area. These landforms are vertically aggrading deposits that are longiuidinally correlative throughout the 65-km study reach. The suite of surfaces identified includes a terrace that is inundated by rare pre- or post-dam floods, an intermediate bench that is inundated by rare post-dam floods, and a post-dam flood plain that is inundated by the post-dam mean annual flood. Analysis of historical photographs in the study reach shows that both the intermediate bench and post-dam flood plain are landforms that were not present in any of the 6 years for which photographs were examined between 1871 and 1954. Photographic replications also show that gravel bars consisting of bare gravel in 1922 and earlier photographs are now covered by fine-grained alluvium and vegetation. Decreased gravel-bar mobility is indicated by estimates of critical and average boundary shear stress. Comprehensive surficial geologic mapping of the study area indicates that the bankfull channel has decreased in width by an average of about 20 percent.

The holotypic locality of the brachiosaurid titanosauriform sauropod, Abydosaurus mcintoshi, is quarry DNM-16, located in Dinosaur National Monument. The bones are preserved near the base of a heterolithic, trough cross stratified to planar bedded sandstone channel complex. The trough cross to planar bedded sandstones mark times of variable flow with times of high flow velocity based on bones whose upper surfaces were eroded before final burial. The abundance of mud with the dominant medium to fine sand, and poorly confined sandstone channels indicate the bones were transported and buried in medial to distal intermittent flows of a distributive fluvial system. The quarry is at the base of the Naturita Formation, the base of which is latest Albian in age. The sauropods lived and died in the middle Cretaceous as the Cretaceous seaway advanced southward. The unconformity below the Naturita Formation and on top of the underlying the Ruby Ranch Member represents the LK-2 sequence boundary. The quarry produced ~260 bones, all of which represent Abydosaurus, except for several small theropod teeth, denoting a single catastrophic event acting on a group of sauropods. About one-third of the bones occur in close association or articulation, including three skulls (one articulated with the first five cervical vertebrae), five limbs, and strings of caudal vertebrae. There is no evidence of preburial weathering or breakage, and trample scratch marks are rare. More than 20% of the bones exhibit irregular, mm-scale pits occur on the shafts and the articular ends of limb bones are commonly hollowed out. The irregular pits are termite foraging traces, and hollows indicate extensive mining by these insects. At least seven individuals of Abydosaurus are present, representing at least two ontogenetic stages (juveniles and subadults).Together, these observations indicate the following: (1) the catastrophic death of a sauropod herd; (2) partial carcass maceration; (3) minor transportation, including articulated units (skulls, vertebrae, limbs); (4) rapid burial in migrating, ephemeral, branches of a distributary fluvial system; (5) channel migration resulting in in-situ scouring of the upper surface of some bones; (6) burial of scoured bones. Termite infestation occurred both prior to, and after, fluvial entrainment and burial.

The Carnegie Quarry in northeastern Utah is world-renowned for the dinosaur skeletons it has produced and for its in situ display of dinosaur bones. The specimens excavated at Carnegie Quarry are displayed and curated in 20 repositories, most in North America. Data on these specimens in the forms of notes, photographs, publications, field maps, and so on, are scattered in an array of formats and institutions. The primary goal of this thesis is to develop a database linking these data with a digital map (GIS system) to make them readily accessible. To this end, a relational database was created using Microsoft Access linked to a vector-based map developed using Avenza MAPublisher running in Adobe Illustrator. Analyzing these data, the Carnegie Quarry produced 4146 specimens representing at least 105 individuals pertaining to 18 genera; 12 dinosaurs, one crocodylomorph, two turtles, Unio utahensis (a freshwater clam), and one plant. The map is based on high resolution photographs of the current quarry face merged with historic maps of previously excavated portions of the quarry. Previous attempts to develop a complete map were hindered by the large number of maps, primarily from four institutions that excavated at the site, and the lack of an accurate map of the current quarry face (due to substantial relief, the 67° dip of strata, and the lack of a permanent grid). The new maps will provide invaluable insights into the depositional setting, taphonomy and paleoecology of the site. The map and database provide a single access point for data on specimens from 20 widely dispersed repositories linking them their original quarry positions. This expandable tool will be invaluable to scientists and the caretakers of Dinosaur National Monument and is recommended for adoption at other quarries.

The Green River canyons of the eastern Uinta Mountains have experienced a 5- year period of high debris flow activity. Catchment factors were studied in watersheds and on debris fans with recent debris flows, leading to the development of a conceptual framework of the hillslope and debris flow processes that deliver sediment to the Green River. Two recent fan deposits were monitored to determine the magnitude and processes of reworking that occur during mainstem floods of varying magnitude. The dominant debris flow initiation mechanism, termed the firehose effect, occurs when overland flow generated on bedrock slopes cascades down steep cliffs and saturates and impacts colluvium stored in bedrock hollows, causing failure. The dry climate and high strength of bedrock cause hillslopes to be weathering-limited, prohibiting the formation of extensive regolith and vegetative cover. This reduces the degree vegetation regulates geomorphic processes and causes wildfire to have little influence on debris flow initiation. The dry climate and strong rocks also lead to high runoff ratios and steep escarpments that result in debris flow initiation via the firehose effect. This initiation process also dominates in Grand Canyon, where geologic and topographic characteristics are similar, but differs from locations in the Rocky Mountains where fire has a strong influence on debris flow processes. Monitoring of two recently aggraded debris fans shows that mainstem floods with magnitudes as low as 75% of the pre-dam 2-year flood cause significant erosion of fan deposits, whereas floods with magnitudes less than 40% of the pre-dam 2-year flood do little reworking. Armoring of the debris fan surface limited the degree ofreworking done by successive floods. Eroded material was deposited directly downstream of the fan, not at the expansion gravel bar. This depositional location represents a change in the organization of the fan-eddy complex, potentially altering the location of recirculating eddies and associated backwater habitats. These results indicate that the firehose effect may be the dominant initiation processes in the steep canyons of the Colorado Plateau and that dam releases that significantly rework fan deposits are within the operational range of large dams in the Colorado River system.

Dinosaur National Monument, in northwestern Colorado and northeastern Utah, is comprised of 206,409 acres and contains several deer winter ranges. A need for deer studies developed because of winter deer mortality and deteriorating range conditions'on some parts of the Monument. Approximately 500 deer winter on the Yampa Bench and approximately 300 deer winter on the Island Park winter range. These are the two main winter ranges within the Monument. Deer on the Yampa Bench migrated an average of 7.3 air miles to the south and summered on the Blue Mountain Plateau during the summer of 1966. This Plateau is owned by the Bureau of Land Management and private individuals. Deer from the Island Park winter range migrated an average of 22.6 air miles to the northwest in 1967, onto the Diamond Mountain Plateau and the Ashley National Forest. Deer tagged on the Split Mountain winter range were found to travel to the south and west. These deer summered mainly upon private lands. Deer remain on Harpers Corner approximately 10 months of the year until deep snows force them to lower elevations on Yampa Bench in early February and from which they return in early April. Vegetation composition and density data gave evidence that the deer and sheep which use the west end of the Yampa Bench are competing for forage. Carrying capacity data suggest that sheep use of this area be reduced. Carrying capacity data for the Split Mountain range suggest that cattle use should be reduced. If grazing use was kept off this area until June, the grasses would have a better opportunity to put on good growth before utilization of them began. Other winter ranges within the Monument are well within their carrying capacity limits. Thus, a safeguard exists on most winter ranges against deer winter mortality. The physical condition of deer on the Monument's winter ranges was very good during the winters of 1966 and 1967. Consequently, deer winter mortality was found to be slight on the Monument's ranges during these two winters. A few does remain on winter range areas within the Monument to summer. They generally 'use the river islands and the relatively inaccessible canyon slopes as fawning grounds. Nearly all of the deer that winter within the Monument migrate to higher elevations off the Monument to summer. This makes them subject to reduction by hunting. Deer hunting pressure on the hunting units adjoining the Monument has in recent years been sufficient to keep deer numbers within their respective winter range carrying capacities.

Boechera is a large genus of flowering plants whose taxa are found primarily in North America. Boechera vivariensis (S.L. Welsh) W.A. Weber (the Park rockcress) is restricted to the Uintah Basin on Weber sandstone substrates in the vicinity of Dinosaur National Monument and Blue Mountain. The nomenclature of Park rockcress is significantly impacted by the discovery that the type collections of the taxon represent a rare, apomictic diploid resulting from the hybridization between B. thompsonii and an undescribed sexual diploid (to be called Boechera caeruleamontana sp. nov. Allphin and Windham). As a result, greater information is needed regarding how B. vivariensis and B. caeruleamontana. are distributed geographically in the region of Dinosaur National Monument and surrounding areas. Thus, we performed genetic analyses on leaf samples taken from over 50 individuals at known sites of B. vivariensis throughout its geographic range. Individuals from each site were also compared morphologically. We also compared associated plant communities at each site and characterized the soils. In our thorough sampling, we did not pick up B. vivariensis. All individuals sampled belonged to B. caeruleamontana, suggesting that most individuals previously assigned to B. vivariensis, are actually representative of B. caeruleamonanta. Populations of B. caeruleamontana were genetically diverse compared to other Boechera species, most likely indicative of its insect pollination strategy. However, all populations had lower heterozygosity than expected based upon Hardy-Weinberg expectations. Reproductive and genetic data indicated that populations are showing signs of inbreeding. The population at Jones Hole Fish Hatchery was most unique genetically, morphologically, and reproductively.

The present work is a general survey of the vegetation of the Utah portion of the Dinosaur National Monument with special emphasis on some of the ecological aspects of the area. The vegetation ranges from xerophytic plant communities of the lower elevations to mesophytic communities of the higher elevations. Hydrophytic plant communities are also present to a limited extent along the Green River and where seeps or springs arise. Soils vary from fine clay to coarse gravel. The dividing lines between formations is often marked by extreme differences in soil type. During the author's first collecting trip into the Monument in April 1955 the possibility of correlations between geological formations and vegetation was suggested by the occurrence of certain plant species on some of the formations. The presence of a well defined geological section in a relatively short distance makes it possible to determine if such correlations exist.