A series of grazing trials were conducted on high elevation summer range near Cedar City, Utah . Cattle and sheep were stocked alone and in common in .4 hectare (ha) paddocks. Stocking rates were .76 ha/AUM in 1981 and .60 ha/AUM in 1982. Vegetation measurements were taken before and after grazing treatments to quantify vegetation disappearance. Diet samples were collected from esophageally fistulated sheep in the paddocks before grazing treatments were applied. After a predetermined level of forage utilization was achieved, the paddocks were re-sampled by the esophageally fistulated sheep to examine diets consumed from the forage-reduced vegetation. Behavioral observations were made throughout the trials on sheep grazing alone and with cattle. The length of time sheep spent at a feeding station, feeding station interval, was measured. Sheep ate less grass and more forbs and shrubs than cattle. Cattle showed a strong reluctance to browse snowberry (Symphoricarpos oreophilus) even when the herbaceous vegetation was greatly reduced. Utilization of grasses, forbs and shrubs in the common use paddocks did not represent an average of the utilization by cattle and sheep each grazing alone. Cattle and sheep grazing together used more forage, especially snowberry, than calculated from single use averages. The diets of esophageally fistulated sheep were altered by the various grazing treatments. Diets consumed from previously ungrazed paddocks were higher in forbs, in vitro organic matter digestibility (IVOMD) and crude protein (CP) and lower in fiber than those diets consumed after paddocks had been grazed. Sheep consumed diets higher in IVOMD but lower in CP in paddocks previously grazed by sheep than where cattle had grazed alone or in commonly grazed paddocks. Sheep selected diets from the remaining herbaceous layer when grazing after sheep but ate mostly snowberry when grazing after cattle. Diets of sheep consumed subsequent to common use grazing were intermediate containing both snowberry and grasses. Sheep adjusted their feeding behavior as the grazing trials progressed by increasing the number of brief feeding station intervals. This trend was consistent regardless of whether sheep grazed alone or in common with cattle. However, when sheep grazed with cattle, longer feeding station station intervals persisted further into the grazing trials indicating that amounts of acceptable forage per feeding station were not reduced as quickly as when sheep grazed alone.

Resources available for agricultural production were ascertained and trends in their use were studied for seven counties of southwestern Utah. Special consideration was given to cropland, irrigation water, and operating capital as resource restrictions for a linear programming model. Budget data were obtained for crop and livestock enterprises by interviewing farmers and ranchers in the area. Budgets for four representative farm types representing climatic and irrigation differences were made to study crop possibilities. Acreage minimums or maximums for selected crops were established as conservation measures. Budgets were prepared for farm livestock enterprises to use with crop budgets for each representative farm. Results provided profit maximizing enterprise combinations for each representative farm.

A study of the Merriam's wild turkey was conducted March 1972 to August 1973 in southwestern Utah to determine the life history and habitat utilization. Using transects, bio-telemetry, and observational techniques, information on flocking, hen:poult and sex ratios, and approximate dates for spring dispersal, nesting, and hatching was obtained. Turkey observations in relation to habitat variables were used to determine habitat utilization. Except during the spring mating season, male flocks remained apart from other turkeys. Hen flocks in fall and winter consisted of adult hens and juveniles of both sexes. Males dispersed from winter flocks in March, and those that became harem gobblers attracted not more than 3 hens. Egg-laying probably took place from mid-April to mid-May and hatching from mid-May to mid-June. A drop in hen:poult ratios from 1:2.2 in 1972 to 1:0.7 in 1973 was attributed to harsh spring weather. Hens comprised an estimated 60 percent of the population during the study period. Turkeys utilized a faU-winter-early spring habitat of mountain brush and scattered ponderosa pine. Late spring use was associated with a ponderosa pine or aspen-mixed-conifer habitat type. Broods highly used glades dominated by an aspen overstory with intermingling mixed-conifer, while a male flock used mixedconifer clearings at 10,000 feet elevation. The upper and lower limits of turkey range on the study area were 10,000 and 6,000 feet, respectively. Turkeys began spring migration in April and fall migration in late September or early October.

Digital soil mapping (DSM) relies on quantitative relationships between easily measured environmental covariates and field and laboratory data. We applied innovative sampling and inference techniques to predict the distribution of soil properties, soil attributes, taxonomic classes, and dominant vegetation across a 30,000-ha complex Great Basin landscape in southwestern Utah. This arid rangeland was characterized by rugged topography, diverse vegetation, and intricate geology. Environmental covariates calculated from digital elevation models (DEM) and spectral satellite data were used to represent factors controlling soil development and distribution. We investigated optimal sample size and sampled the environmental covariates using conditioned Latin Hypercube Sampling (cLHS). We demonstrated that cLHS, a type of stratified random sampling, closely approximated the full range of variability of environmental covariates in feature and geographic space with small sample sizes. Site and soil data were collected at 300 locations identified by cLHS. Random forests was used to generate spatial predictions and associated probabilities of site and soil characteristics. Balanced random forests and balanced and weighted random forests were investigated for their use in producing an overall soil map. Overall and class errors (referred to as out-of-bag [OOB] error) were within acceptable levels. Quantitative covariate importance was useful in determining what factors were important for soil distribution. Random forest spatial predictions were evaluated based on the conceptual framework developed during field sampling.

Hydrogeologically important features of fault zones include undamaged country rock, the damage zone, and the core zone. Fault cores generally have low porosity and permeability, and often act as a barrier to groundwater flow. The damage zone, by contrast, consists of small faults and fracture networks, which can act as conduits. Timpoweap Canyon near Hurricane, Utah has superb exposures of the fault core and damage zone of the Hurricane Fault. Also within the canyon, springs discharge from the damage zone into the Virgin River, providing an ideal natural laboratory for the study of groundwater discharge from a fault zone. The Hurricane fault is an active, steeply dipping, normal fault that is 250 km long, and exhibits about 2500 m of displacement. The damage zone in Timpoweap Canyon controls thermal groundwater (~40°C) and CO2 gas discharge from highly fractured limestone. Total spring discharge is 260 L/s. Approximately 4 L/s of CO2 gas also discharges with the springs. The δ^2H and δ^16O composition of the springs exhibits a geothermal shift from the global meteoric waterline. This suggests that the circulation depth is about 3 km below the ground surface (bgs) in basement bedrock. The CO2 gas discharging originates from either magmatic sources or from diagenesis. The fracture density in a typical damage zone decreases with increasing distance from the fault, thus spring discharge should also decrease with increasing distance from the fault. The damage zone in Timpoweap Canyon does not follow this pattern because pre-existing fractures that developed from Laramide and Sevier Orogeny stresses suppress the pattern. Collapse structures from gypsum dissolution and large fractures also control the location of spring discharge.