Wasatch Mountains Research Articles

Growth and reproductive responses of true mountain mahogany to browsing

True mountain mahogany (Cercocarpus montanus Raf.) compensates for annual growth lost to browsing under conditions of high resource availability. To develop better guidelines for its management for big game winter forage, twig demography was studied under natural herbivory and resource availability inside and outside exclosures at 1 site in the Wasatch Mountains and on 4 sites on the North Slope of the Uinta Mountains, Utah. Annual and previous years' twig lengths, as well as location and numbers of flowers and seeds were diagrammed on branches of browsed and unbrowsed shrubs in the spring or summer and fall between 1996 and 1999. Annual twig growth and flower and seed numbers of both browsed and unbrowsed shrubs were greatest in 1997 or 1998 when precipitation was highest. Utilization of annual growth varied among sites within a year and among years within a site and ranged from < 21 % to > 300 % when previous years' growth was browsed. Despite differences in utilization, browsed twigs compensated similarly for length lost to herbivory, so that total twig lengths remained the same over the course of the study. Although twigs on unbrowsed shrubs had less annual growth per unit branch length than those on browsed shrubs, lack of length lost to herbivory resulted in an increase in total twig length over time. Years of high resource availability are important in allowing grazing tolerant shrubs such as true mountain mahogany to compensate for years of heavy utilization. Flower and seed numbers were much higher (P < 0.05) on unbrowsed than browsed shrubs. Compensatory growth was enough to maintain, but not increase total twig lengths after high utilization (> 100 %) even on years of high resource availability.

Potential effects of ozone, climate, and spruce budworm on Douglas-fir growth in the Wasatch Mountains

This study assessed the potential for ozone injury to vegetation in the central Wasatch Mountains of Utah by determining if Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) experienced reduced growth since the onset of high ozone concentrations. Dendrochronological techniques were used to model Douglas-fir growth in six central Wasatch Mountain stands, where ozone concentrations suggest the possibility of injury to vegetation, and in four Bear River stands, where ozone concentrations are lower than injury thresholds. Previous-year growth, temperature, and Palmer's Z index variables explained 53–70% of the variance in annual growth. Reduced Douglas-fir growth, not explained by the model or insect and disease records, occurred after 1970 in the central Wasatch Mountains but not in the Bear River Mountains. Douglas-fir growth in the central Wasatch Mountains was slightly negatively correlated with the previous-year ozone concentrations in nearby Salt Lake valley. Between 1962 and 1973, a fluctuating budworm population due to varying spring precipitation was suggested to have replaced precipitation as the factor limiting tree growth, causing an anomalous negative relationship between precipitation and Douglas-fir growth. Because of a suite of possible factors (e.g., undetected climatic variables, fungal pathogens, competitive interactions) influencing Douglas-fir growth, ozone may be one factor in a larger stressor complex reducing growth.

The Lady in the Ore Bucket: A History of Settlement and Industry in the Tri-Canyon Area of the Wasatch Mountains

The Lady in the Ore Bucket: A History of Settlement and Industry in the Tri-Canyon Area of the Wasatch Mountains

The influence of thermally driven circulation on PM 10 concentration in the Salt Lake Valley

Ground level and vertical measurements of aerosols (PM 10) and meteorological parameters in the Salt Lake Valley were conducted as a part of the Vertical Transport and MiXing in the atmospheric boundary layer (VTMX) experiment, conducted during the period 1–18 October 2000. This component of the VTMX experiment was directed toward developing a deeper understanding of the factors affecting the distribution and transport of pollutants in urban areas within complex terrain. The present study focused on the temporal (diurnal) and vertical variation of PM 10 concentration during the stable nighttime period as well as the morning and evening transition periods. The temporal variations in the aerosol concentration during these periods was dominated by thermally driven diurnal winds, with only minor influences from background synoptic winds. The increased aerosol concentration between sunrise and the afternoon was associated with the westerly up-slope winds that advected PM 10 from the nearest source, the downtown area of Salt Lake City. In mid-afternoon the PM 10 concentration decreased significantly due to the arrival of a northwesterly lake breeze near the ground. The lowest aerosol concentrations during the period from late afternoon to early morning are the result of the draining of cleaner air from the mountain slope after the wind shifted from westerly to easterly. The temporal variations in the wind direction and aerosol levels during the nighttime are discussed. A hypothesis is advanced, with some supporting evidence, that periodic variations of the nighttime PM 10 concentrations owe to the shedding of vortices from the Wasatch mountain range bordering the lake. The vertical distribution of aerosols is sensitive to the thermal forcing, which exerts the driving influence on thermal circulation within the Salt Lake Valley.

Salt Lake City Meeting Highlights

With two spectacular geographic features (the great Salt Lake and the Wasatch Mountain Range) as its borders, Salt Lake City provided a gorgeous setting for the Society’s 202nd meeting.

Meeting Program: 202nd Meeting of The Electrochemical Society - Salt Lake City, UT (October 20-24, 2002)

Welcome to Salt Lake City – the host city of the 2002 Winter Olympic Games, and the site of the 202nd Meeting of The Electrochemical Society. Salt Lake City lies in a mountain valley in the Wasatch Mountains and is home to historic temples, art galleries, and museums, as well as the world’s largest genealogical library.

The agricultural dispersal‐valley drift spray drift modeling system compared with pesticide drift data

The coupling of the valley drift (VALDRIFT) atmospheric dispersion/deposition model with the agricultural dispersal (AGDISP) aircraft wake model generates a modeling system for predicting the off-target drift of pesticides sprayed in a mountain valley. The approach uses the AGDISP near-field spray model to estimate the mass fraction of pesticide remaining airborne after initial application, then the VALDRIFT complex terrain model to estimate the drift of pesticide from the target area. The modeling system inputs include detailed spray information, a measure (or estimate) of winds in the valley, and the valley topographic characteristics; the results are pesticide concentrations throughout the valley atmosphere and pesticide deposition to the valley surface. The AGDISP and VALDRIFT models are operated independently, with the results from AGDISP being used as input to VALDRIFT through user-created data files. The modeling system was evaluated using pesticide drift data from spray trials conducted in the Mill Creek Canyon of Utah's Wasatch Mountains, USA, during the late spring of 1993. The predicted deposition compared within a factor of three of the observations (70% of the time) at all sampling locations extending several kilometers down-valley from the spray treatment block. The overall average ratio of predicted-to-observed deposition was 0.9.

Weather Support for the 2002 Winter Olympic and Paralympic Games

Abstract The 2002 Winter Olympic and Paralympic Games will be hosted by Salt Lake City, Utah, during February-March 2002. Adverse weather during this period may delay sporting events, while snow and ice-covered streets and highways may impede access by the athletes and spectators to the venues. While winter snowstorms and other large-scale weather systems typically have widespread impacts throughout northern Utah, hazardous winter weather is often related to local terrain features (the Wasatch Mountains and Great Salt Lake are the most prominent ones). Examples of such hazardous weather include lake-effect snowstorms, ice fog, gap winds, downslope windstorms, and low visibility over mountain passes. A weather support system has been developed to provide weather information to the athletes, games officials, spectators, and the interested public around the world. This system is managed by the Salt Lake Olympic Committee and relies upon meteorologists from the public, private, and academic sectors of the atm...

Understanding Utah Winter Storms: The Intermountain Precipitation Experiment

Abstract Winter storms and their prediction are of increasing importance throughout the region of the United States with the fastest growing population, the Intermountain West. Such storms can produce heavy orographic snowfall, lake-effect snowbands, and even lightning. Unfortunately, precipitation forecast skill is lower over the Intermountain West thanother regions of the country because of the complex topography, the lack or limited utility of upstream and in situ data, and insufficient understanding of storm and precipitation processes. The Intermountain Precipitation Experiment (IPEX) is a research program designed to improve the understanding, analysis, and prediction of precipitation over the complex topography of the Intermountain West. The field phase of this research program was held in northern Utah in February 2000. During this time, seven storms were observed, including the heaviest snowfall to strike the Wasatch Mountains in two years, a tornadic bow echo associated with a strong cold front,...

Sources of Fine Particulate Material along the Wasatch Front

The concentration and composition of PM2.5 has been measured with a variety of continuous and integrated samplers at the Hawthorne EPA Environmental Monitoring for Public Awareness and Community Tracking (EMPACT) sampling site in Salt Lake City, UT, and at an EPA Science to Achieve Results (STAR) sampling site in Bountiful, UT. Data are considered at both sites during a 10-day winter period with high PM2.5 concentrations due to winter inversions, and at the Hawthorne site only during a fourteen day summer period when the site was impacted by smoke from wildfires in the Wasatch Mountains. The PM2.5 was dominated by organic material and ammonium nitrate in the winter and by organic material in the summer. In both cases, substantial amounts of sem-volatile material, SVM, was present which was not measured by a Tapered Element Oscillating Microbalance (TEOM) monitor but was detected by a Real-Time Ambient Mass Sampler (RAMS). The PM2.5 data have been combined with concentrations of particulate soot and soil c...

Stoneflies (Plecoptera) Of Southern Utah With An Updated Checklist Of Utah Species

Southern Utah comprises 4 major physiographic divisions: the Great Basin, Colorado Plateau, Central Rocky Mountains, and Southern Rocky Mountains, which have been partitioned into faunal regions. We discuss the uniqueness of southern Utah and the amount of land set aside for recreation and preservation, and we encourage the study and preservation of its water resources. The stonefly (Plecoptera) fauna of 13 counties in southern Utah was sur- veyed. We found 58 species representing 34 genera and 8 families. Three new state records for Utah and many new county records for southern Utah are presented, along with a discussion of distribution patterns and faunal affinities of each species. Distribution patterns indicate a historical connection between the Sevier River and the Colorado drainage and a separation of faunal areas within the Central Rocky Mountains at boundaries between the Wasatch Mountains, Wasatch Plateau, and the Southern High Plateau. The uniqueness of the isolated Abajo and LaSal Mountains, the Virgin River valley, and other faunal areas in southern Utah is presented.

Origin and emplacement of igneous rocks in the central Wasatch Mountains, Utah

The calc-alkaline igneous rocks in the central Wasatch Mountains were emplaced between 36–30 Ma. They form a belt comprised of eleven stocks and the Keetley volcanic field aligned along the crustal suture between the Archean Wyoming province and accreted Paleoproterozoic terranes. Magmatism associated with this belt and its westward continuation into the Bingham mining district has been related to mid-Cenozoic extension. These rocks consist of two types of stocks based on texture: a western type, which is coarse grained, and mostly equigranular, and an eastern type (including the Keetley volcanic rocks), which is fine grained and porphyritic. The compositional variation in the western stocks (Little Cottonwood, Alta, and Clayton Peak stocks) forms three distinct compositional groups. The compositional variation in the eastern stocks is similar to the compositional variation in the Alta stock. Major and trace element variations in these rocks resemble those of subduction-related magmas. However, the high K2O contents and low esr values are not consistent with this origin. These magmas formed from melting of mafic igneous rocks. We propose that magmas were generated by decompression melting due to gravitational collapse of the crust that had been thickened during Cretaceous to early Cenozoic deformation. Magmas rose to varying levels in the crust along an east–west lineament. The igneous rocks of the central Wasatch Mountains have eNd(t) similar to most of the Phanerozoic igneous rocks in the miogeocline (MG), but have significantly lower eSr(t). That anomaly has been explained as due to melting of a basement long depleted in Rb (Farmer and DePaolo, 1983, 1984). However, the Wasatch igneous belt rocks are high-potassium, calc-alkaline rocks and all have very similar incompatible trace element patterns, whereas only a few MG rocks are calc-alkaline or high potassium. Furthermore, in the MG rocks incompatible trace element patterns are variable. One possible explanation for the dilemma of long-time depletion of Rb in these high-potassium, calc-alkaline rocks is that the crust may have been recently charged with Rb and K during the Sevier-Laramide event (100–40 Ma) by dehydration of the subducting slab. This event was followed by melting during mid-Cenozoic collapse of the orogen (ca. 40–20 Ma). The source of the magmas was melting of mafic rocks in the lower crust. Some of these magmas ponded, formed magma chambers, and differentiated. Some involved little ponding and erupted directly on the surface in the form of the Keetley volcanic field. Continued melting and extension produced new magmas from a similar crustal source. These magmas were emplaced below a series of pull-apart structures associated with strike-slip displacement along an east–west suture. This suture may have been controlled by the Archean-Proterozoic boundary. Some magma bodies were emplaced quickly to the surface without significant fractionation. Others coalesced and fractionated over a protracted period of time. These magma bodies interacted with crustal rocks, and differentiated to relatively evolved compositions.

Normal fault thermal regimes and the interpretation of low-temperature thermochronometers

Exhumation rates inferred from thermochronometers are dependent on spatial and temporal variations in temperature. In active extensional mountain belts, the temperature field is complicated by tectonic and surface processes including: (1) lateral heat flow across large, range-bounding normal faults due to the juxtaposition of a cool hanging wall and a relatively warmer footwall, (2) uplift and erosion of the footwall, (3) sedimentation and burial of the hanging wall, (4) lateral heat refraction around low thermal conductivity sediments deposited in the hanging wall basin, and (5) 3D temperature variations due to high-relief topography developed on the footwall. We explore these mechanisms through a series of 2D conductive thermal models designed to investigate the effect of tectonics and topography on apatite fission track (AFT) and (U–Th)/He thermochronometer data. Models were tuned to the geometry and kinematics of the Wasatch Mountains, Utah, USA. The principal parameters in our model are exhumation and burial rates ranging from 0.2 to 5.7 mm per year at the range front and decreasing with distance from the fault, surface morphology taken from USGS digital elevation models, and basin geometries inferred from seismic and gravity surveys. Predicted AFT and (U–Th)/He ages were generated using cooling rate dependent annealing and diffusion kinetic models. Results indicate after 10 million years of exhumation, footwall (U–Th)/He and AFT closure temperature isotherms within 10 km of the fault are advected upward 500 and 1000 m, respectively, from their initial position. The upward advection of isotherms and the 2D nature of the thermal regime can result in erroneous exhumation rates calculated from plots of sample elevation versus age using 1D thermal models. For simulations with a uniform vertical uplift rate and canyon and ridge topography, 1D and 2D exhumation rate differences were 20–70% for (U–Th)/He and ∼10% for AFT data. Samples collected perpendicular to fault strike up the range front are sensitive to the exhumation rate and footwall tilt. Differences between 1D and 2D range front exhumation rates were 10–95% for (U–Th)/He and 10–40% for AFT data. Furthermore, 1D thermal models are incapable of deciphering footwall tilt. At simulated exhumation rates of 3, 4, and 5 mm per year predicted (U–Th)/He and AFT ages form closely spaced, near vertical lines on a plot of elevation versus sample age, therefore, suggesting a decreased sensitivity of data to topography and surface processes at high exhumation rates. Despite large errors in previously collected AFT data from the Wasatch mountains, our model suggests a revised fault-adjacent exhumation rate of 0.5–0.6 mm per year compared to previous estimates of 0.7 mm per year based on 1D thermal models.

EFFECT OF DENSITY REDUCTION ON UINTA GROUND SQUIRRELS: ANALYSIS OF LIFE TABLE RESPONSE EXPERIMENTS

The effects of natural or experimental environmental perturbations on pop- ulations can be diverse, simultaneously affecting several life history variables. Population- level responses to such influences frequently are measured as changes in projected popu- lation growth rate (l). Sensitivity and elasticity analyses can be used to quantify the potential influence of small changes in different life history variables on l. When a population is subjected to an experimental treatment, life table response experiment (LTRE) analysis allows decomposition of changes in l into contributions due to observed changes in in- dividual life history variables. We investigated the potential and actual influence of de- mographic characteristics (age at maturity, juvenile and adult survival, fertility, and age at last reproduction) on l of Uinta ground squirrels (Spermophilus armatus) in the Wasatch Mountains of Utah, USA. Ground squirrels were studied in three different habitats, before and after an experimental reduction of population size. Survival and reproduction of squir- rels increased in response to a reduction in population density. Consequently, l increased by at least 21% in two of the three habitats. Population growth rate was potentially most sensitive to changes in age at maturity (a) and fertility. LTRE analysis revealed that a did not change and contributed nothing to changes in l, but changes in fertility were large and contributed most to observed changes in l. Age at last reproduction (v) increased after density reduction but contributed little to observed changes in l because of low sensitivity of l to changes in v. Thus, there was little correspondence between potential influence and actual contributions to observed changes in l. We concluded that some demographic var- iables, notably a, had little environmental or phylogenetic scope for reduction, whereas fertility and to some degree survival rates were considerably more plastic under the ex- perimental treatment. Because LTRE analysis incorporates observed changes in life history variables and also sensitivity of l to these changes, it worked well for quantifying the response of Uinta ground squirrel populations to density manipulation and holds promise for evaluating alternative management strategies in conservation biology.

Ownership of Mine‐Tunnel Discharge

AbstractWater discharging from numerous tunnels constructed during mining in the Wasatch Mountains near Salt Lake City, Utah, flows into nearby creeks. Disputes over ownership of water feeding the creeks have resulted in extensive litigation. In the course of a legal dispute over ownership of outflow from the Kentucky‐Utah (K‐U) Tunnel we evaluated the patterns and rates of ground water flow using an integrated study of the geology, chemistry, isotopes, and chlorofluorohydrocarbon (CFC) composition of the water. A sequence of sedimentary rocks with a range of hydraulic conductivity values has been folded, faulted, intruded by igneous rocks, and then eroded to create the rough topography of the Wasatch Mountains. The similarity of composition among tunnel discharge, springs, and base flow in the creek indicates that the creek is fed by ground water circulating in local, shallow flow systems. Results of numerical simulations of ground water flow indicate that the K‐U Tunnel likely intercepts ground water that, in the absence of the tunnel, would ultimately flow in the subsurface to Big Cottonwood Creek. CFC and tritium contents of the water indicate flow weighted average ground water travel times range from four to 23 years and support our conclusion that water discharging from the tunnel is moving within a shallow ground water flow system. Despite sparse data, the scientific understanding was deemed sufficient for the judge to rule that owners of the surface water also own the tunnel discharge because, in the absence of the tunnel, this water would supply the stream.

Particulate Air Pollution and Daily Mortality on Utah's Wasatch Front

Reviews of daily time-series mortality studies from many cities throughout the world suggest that daily mortality counts are associated with short-term changes in particulate matter (PM) air pollution. One U.S. city, however, with conspicuously weak PM-mortality associations was Salt Lake City, Utah; however, relatively robust PM-mortality associations have been observed in a neighboring metropolitan area (Provo/Orem, Utah). The present study explored this apparent discrepancy by collecting, comparing, and analyzing mortality, pollution, and weather data for all three metropolitan areas on Utah's Wasatch Front region of the Wasatch Mountain Range (Ogden, Salt Lake City, and Provo/Orem) for approximately 10 years (1985-1995). Generalized additive Poisson regression models were used to estimate PM-mortality associations while controlling for seasonality, temperature, humidity, and barometric pressure. Salt Lake City experienced substantially more episodes of high PM that were dominated by windblown dust. When the data were screened to exclude obvious windblown dust episodes and when PM data from multiple monitors were used to construct an estimate of mean exposure for the area, comparable PM-mortality effects were estimated. After screening and by using constructed mean PM [less than/equal to] 10 microm in aerodynamic diameter (PM10) data, the estimated percent change in mortality associated with a 10-mg/m3 increase in PM10 (and 95% confidence intervals) for the three Wasatch Front metropolitan areas equaled approximately 1. 6% (0.3-2.9), 0.8% (0.3-1.3), and 1.0% (0.2-1.8) for the Ogden, Salt Lake City, and Provo/Orem areas, respectively. We conclude that stagnant air pollution episodes with higher concentrations of primary and secondary combustion-source particles were more associated with elevated mortality than windblown dust episodes with relatively higher concentrations of coarse crustal-derived particles.

Particulate air pollution and daily mortality on Utah's Wasatch Front.

Reviews of daily time-series mortality studies from many cities throughout the world suggest that daily mortality counts are associated with short-term changes in particulate matter (PM) air pollution. One U.S. city, however, with conspicuously weak PM-mortality associations was Salt Lake City, Utah; however, relatively robust PM-mortality associations have been observed in a neighboring metropolitan area (Provo/Orem, Utah). The present study explored this apparent discrepancy by collecting, comparing, and analyzing mortality, pollution, and weather data for all three metropolitan areas on Utah's Wasatch Front region of the Wasatch Mountain Range (Ogden, Salt Lake City, and Provo/Orem) for approximately 10 years (1985-1995). Generalized additive Poisson regression models were used to estimate PM-mortality associations while controlling for seasonality, temperature, humidity, and barometric pressure. Salt Lake City experienced substantially more episodes of high PM that were dominated by windblown dust. When the data were screened to exclude obvious windblown dust episodes and when PM data from multiple monitors were used to construct an estimate of mean exposure for the area, comparable PM-mortality effects were estimated. After screening and by using constructed mean PM [less than/equal to] 10 microm in aerodynamic diameter (PM10) data, the estimated percent change in mortality associated with a 10-mg/m3 increase in PM10 (and 95% confidence intervals) for the three Wasatch Front metropolitan areas equaled approximately 1. 6% (0.3-2.9), 0.8% (0.3-1.3), and 1.0% (0.2-1.8) for the Ogden, Salt Lake City, and Provo/Orem areas, respectively. We conclude that stagnant air pollution episodes with higher concentrations of primary and secondary combustion-source particles were more associated with elevated mortality than windblown dust episodes with relatively higher concentrations of coarse crustal-derived particles.

Environmental Persistence ofBacillus thuringiensisSpores Following Aerial Application

Soil and leaf populations ofBacillus thuringiensis(Bt) were monitored following aerial application of commercial Bt formulations at the rate of 72 billion international units per acre per year during a 5-year period. Data from soil sample spore counts suggested that Bt spores persisted in Wasatch forest soils for up to 2 years but they did not proliferate. Bt isolates were recovered from leaf samples 12 months post application from sprayed, previously sprayed and from nonsprayed areas. The frequency and diversity of Bt isolates recovered from leaves was independent of sample area spray history. In accordance with U.S. Forest Service criteria, aerial application of Bt during a 5-year period resulted in the eradication of gypsy moth (Lymantria dispar,L) from the Wasatch Front region of the Wasatch Mountain Range, Utah.

In times of change learners inherit the earth. The 1997 presidential address.

Neurosurgery, as traditionally practiced, is changing. Eric Hoffer observed, "In times of change learners inherit the earth; while the learned find themselves beautifully equipped to deal with a world that no longer exists." Historically, learners have possessed certain attributes. They anticipate rather than react to change. They become essential facilitators within their altered environment. They are effective advocates for principled behavior and ethical practices. They skillfully communicate the new and technically arcane with a common touch. Learners also understand the lessons of history. The potential of process technology, illustrated by Morton's 1846 application of already well-understood science, in essence, to transform the profession of surgery by making painless operations possible, is one example. Voluntary professional associations such as organized neurosurgery can also learn from the contrasting experiences of the Donner Party and the Utah Pioneers as they made their way down the same canyon of the Wasatch mountain range during the summers of 1846 and 1847, respectively. Group dynamics during those two episodes differed strikingly. It was the vanguard party of Utah Pioneers who exemplified the characters of learners. They acted with unity, common purpose, and careful preparation designed to benefit those who followed them. Years from now, how will the current individual and institutional behavior of neurosurgeons and their associations be judged? An interval assessment is suggested at the April, 2012 American Association of Neurological Surgeons Annual Scientific Meeting. From that perspective, will it be determined that the neurosurgical discipline acted presciently, as would those Hoffer describes as learners? Will neurosurgery be said to have understood and thereby profited from the lessons of history? These are pertinent questions. The answers, considered as a proposed progress report 15 short years from now, could accurately predict the scientific and professional position that neurological surgery will occupy in the future. Deserved long-term success based on the effective, far-sighted behavior exhibited by learners is my confident expectation.

The 1997 Alta Conference: Twenty Years in the Making

When the Tenth Biennial SCA/AFA Summer Conference on Argumentation convened on July 31, 1997, in the Wasatch Mountains at Alta, Utah, it was a conference twenty years in the making. The authors and critics polished their papers throughout the spring and early summer of 1997, the conference committee put all of the last minute touches on local arrangements, and conference director Jim Klumpp watched all the efforts come together, generated by the hard work that he and his conference committee have done over the last two years since the 1995 conference. But beyond all of these preparations stretches a history, a long gray line of committees, individuals, paper presenters, editors, and local arrangements committee members, who made the 1997 Alta Conference in reality the product of two decades of planning and evolution. The Alta Conference in fact had its beginning in 1976 when David Zarefsky, who then served as Chair of the SCA Forensics Division, appointed a planning committee to investigate the possibility of a summer conference in argumentation. Subsequent chairs of the division also continued to appoint committees for this purpose. These chairs included Donn W. Parson, J. Robert Cox, and David Thomas. By 1978 the University of Utah had been selected as host institution for the conference, and the American Forensic Association had joined the undertaking as a co-sponsor. At the time of the entry of the American Forensic Association into the conference planning, Gerald H. Sanders, then at the College of Wooster, was president of AFA. The reorganized planning committee then began its work in earnest at the Minneapolis convention of the SCA and AFA in the fall of 1978. After several months of planning and preparation, the first summer conference convened at Rustler Lodge in Alta, Utah, on July 26, 1979. Since 1979, the four-day format of the conference has remained, for the most part, little changed. Participants gather at Alta on Wednesday evening or Thursday morning of the conference, with a late lunch buffet being served upon arrival and with a keynote address either in the afternoon or evening on Thursday. Two days of heavily scheduled conference participation follow on Friday and Saturday, and over the years various efforts have been made to provide appropriate breaks in the afternoon and evening so that colleagues may digest the materials being presented to them and engage in scholarly interchange of ideas in a collegial fashion. There is typically very little actual conference business conducted on the Sunday on which the conference adjourns, and a concluding brunch is served at the conference hotel. While the format of the conference has not changed to any appreciable degree, and while the purpose of the conference remains fairy constant - to bring together interested scholars from around the world to share ideas about argumentation - there have been some significant changes in the scope of the Alta Conference over the years. One need only glance at the conference proceedings to learn some of the dimensions of change. While there has typically been, as befits the co-sponsorship by the American Forensic Association, a serious attempt to include a section on Argumentation and Forensics, there has been considerable variety in the other areas of interest at specific conferences. The first conference in 1979 featured three areas of interest: Argumentation and the Law, Argumentation Theory and Criticism, and Argumentation and Forensics. During the course of the conference in 1979 most of the conferees attended at least one session in each of the three areas. Conference planners hoped that this arrangement would allow for maximum choice between specialization and diversity of interests. While the practice of collegiality and the tone of the conference have continued as originally envisioned, an observer of the last several conferences might well conclude that there has been some falling away from the original intention of providing a series of programs designed to meet the general interests of all conferees attending. …