Geology topics

Research about Dinosaur National Monument

Source-linked reports with geographic coverage including Dinosaur National Monument.

5 recordsLinked to original sources

USGS2026

Ecology of reintroduced Rocky Mountain bighorn sheep in Dinosaur National Monument

Translocations have been widely used to restore and conserve bighorn sheep ( Ovis canadensis ) populations in North America. Some translocations have been successful, but many populations remain small and genetically isolated. Population structure can influence the viability and long-term success of reintroductions. Social ungulates often function as interconnected subpopulations (metapopulations); however, few studies evaluate subpopulation sizes, connectivity, and genetic diversity within metapopulations. To address this gap, we conducted a comprehensive study of a reintroduced Rocky Mountain bighorn sheep ( Ovis canadensis canadensis ) population in Dinosaur National Monument in Colorado and Utah, USA, between 2006–2020. We analyzed global positioning system (GPS) radio-collar data, genetic samples, and results of health testing to evaluate abundance, distribution, genetic structure and diversity, habitat use, movement and connectivity, and presence of or exposure to respiratory pathogens. We integrated these analyses to evaluate the outcomes of a reintroduction effort that began in 1952, over 70 years ago, and to inform management decisions in Dinosaur National Monument. We also provide a framework for evaluating metapopulation processes, including a non-invasive approach that links genetic structure with Bayesian spatial capture-recapture analyses to estimate subpopulation sizes. Despite models indicating continuous suitable habitat, we found a spatially structured population with at least 4 subpopulations with constrained connectivity. Evidence from step selection and density analyses suggested that movement among subpopulations may be limited by semi-permeable barriers including rivers and human disturbance, which could contribute to maintenance of spatial structure over time. In 2006, antibody to Mycoplasma ovipneumoniae was detected in all geographically and genetically distinct subpopulations. Widespread clinical signs of disease and a confirmed exposure to M. ovipneumoniae in 2019 indicate a long-term disease challenge. Proximity to domestic sheep creates repeated opportunities for introduction of new M. ovipneumoniae strains. We estimated abundance in 2019 at 109 (95% CrI = 87–133), composed of subpopulations ranging from 18–39 animals (95% CrIs from 11–50). Genetic diversity was relatively high compared to other reintroduced and native Rocky Mountain bighorn sheep populations, which is likely a consequence of multiple translocations from different sources. Three of 4 subpopulation centers generally aligned with the locations of original translocation release sites. Persistence in the presence of pathogens may be facilitated by metapopulation structure and moderately high genetic diversity. Conversely, metapopulation structure can also facilitate pathogen persistence. Our approach offers a path to advance understanding of the population ecology of reintroduced bighorn sheep and can inform effective conservation and management of their populations.

Colorado, Wyoming↗

USGS2013

Characterization of hydrodynamic and sediment conditions in the lower Yampa River at Deerlodge Park, east entrance to Dinosaur National Monument, northwest Colorado, 2011

The Yampa River in northwestern Colorado is the largest, relatively unregulated river system in the upper Colorado River Basin. Water from the Yampa River Basin continues to be sought for a number of municipal, industrial, and energy uses. It is anticipated that future water development within the Yampa River Basin above the amount of water development identified under the Upper Colorado River Endangered Fish Recovery Implementation Program and the Programmatic Biological Opinion may require additional analysis in order to understand the effects on habitat and river function. Water development in the Yampa River Basin could alter the streamflow regime and, consequently, could lead to changes in the transport and storage of sediment in the Yampa River at Deerlodge Park. These changes could affect the physical form of the reach and may impact aquatic and riparian habitat in and downstream from Deerlodge Park. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, began a study in 2011 to characterize the current hydrodynamic and sediment-transport conditions for a 2-kilometer reach of the Yampa River in Deerlodge Park. Characterization of channel conditions in the Deerlodge Park reach was completed through topographic surveying, grain-size analysis of streambed sediment, and characterization of streamflow properties. This characterization provides (1) a basis for comparisons of current stream functions (channel geometry, sediment transport, and stream hydraulics) to future conditions and (2) a dataset that can be used to assess channel response to streamflow alteration scenarios indicated from computer modeling of streamflow and sediment-transport conditions.

Colorado↗

USGS1978

Hydrologic reconnaissance of the Yampa River during low flow, Dinosaur National Monument, northwestern Colorado

A hydrologic reconnaissance of a 74-kilometer reach of the Yampa River in Dinosaur National Monument was made during low flow in mid-August 1976. Stream discharge, which was measured along this reach every 16 to 24 kilometers, ranged from 9.4 to 10.6 cubic meters per second. Variations in streamflow were explained, in part, by underflow, loss to ground water, and evaporation. Specific conductance was measured about every 2 kilometers and indicated a downstream increase on the order of 11 to 12 percent for the reach. Except for mercury, bottom-sediment trace-element concentrations in the study reach were less than maximum concentrations determined during August-September 1976 for bottom sediments at unperturbed sites upstream in the Yampa River basin. At one of five sampling sites, the mercury concentration in bottom sediments exceeded the maximum measured upstream level.

Colorado↗

USGS1976

Water resources of Dinosaur National Monument, Colorado and Utah

Dinosaur National Monument, partly in the Rocky Mountain System and partly in the Colorado Plateaus physiographic province, covers an area of 322 square miles (834 square kilometres) in northwestern Colorado and northeastern Utah. The climate is generally cool and pleasant in May, early June, September, and October; winters are cold. Normal annual precipitation ranges from less than 8 to more than 16 inches (203 to 406 millimetres). Geologic formations in the monument range in age from upper Precambrian to Holocene, but not all ages are represented. The monument is on the south limb of the east-trending regional fold representing the Uinta Mountains. Faults and subsidary folds on the south slope of the Uinta Mountains complicate the geology and hydrology of the area. None of the surface streams in the monument are diverted for public supply, but the Green and Yampa Rivers are a recreational resource for boaters. The flow of the Green River is regulated by Flaming Gorge Reservoir; however, flood potentials are estimated for the Yampa River and three smaller streams. Facilities in the monument are not endangered by probable mean annual floods, but may sustain some damage to facilities by the 25- or 50-year floods. Major aquifers in the monument are sandstone and limestone formations, but these formations are drained in the higher areas. Alluvium along the major stream channels yields small amounts of water to wells, but some of the water is not of suitable chemical quality for public supply. All public water supplies in 1971 were obtained from wells, and the use of water during 1970 was estimated to be 15 million gallons (46 acre-feet or 0.057 cubic hectometres). Most of the ground water obtained from sandstone and limestone is of suitable chemical quality for public supply.

Colorado, Utah↗

USGS1971

Water-resources investigations in Dinosaur National Monument, Utah-Colorado, fiscal year 1970

Water-resources data were acquired during fiscal year 1970 by the U.S. Geological Survey at Dinosaur National Monument, Utah-Colorado, for the U.S. National Park Service as part of a continuing project. The data provide a basis for planning the development, management, and use of the available water resources to provide adequate water supplies. Thirty-one springs, 19 in relatively inaccessible areas, were evaluated as sources of water supplies. Seven potential well sites were evaluated for drilling depths in specific aquifers. A well drilled in Echo Park near the confluence of the Green and Yampa Rivers was tested. The pumping test showed the well to yield 130 gallons per minute with a drawdown of 1.96 feet; specific capacity of the well at 130 gallons per minute is 66 gallons per minute per foot. Water samples for chemical analysis were - collected from nine springs and one well; all except that from Disappointment Spring, were of good chemical quality.

Colorado, Utah↗