Mountain Bighorn Research Articles

Identifying Twentieth Century Dude Ranches in the Teton Valley Region

The states of Wyoming, Montana, and to a lesser extent Colorado are commonly understood as the industrial heartland of U.S. dude ranching in the twentieth and twenty-first centuries (Borne 1983). Though there were earlier small scale efforts to host easterners on ranches in the West from the 1850s onwards, dude ranching is commonly understood to have begun in 1879 in Medora, North Dakota by the Eaton Brothers (Borne 1983, Rothman 1998). Dude ranching--when outsiders pay to stay on a ranch ­ usually demonstrates most/if not all of the following six characteristics: 1). it embraces of the West's nineteenth century agricultural heritage; 2). it celebrates wild, preserved landscapes; 3). it provides an economic vehicle for ranchers to maintain their cultural heritage, and/or investors and managers to have a piece of the American West; 4). it demonstrates a distinct dude ranch aesthetic (architecture, clothing, food, music, stories, education and landscape); 5). it includes horse­related activities; and 6). it provides a safe and contained regional experience transforming the traveler from "mere' tourist status to that of a liminal space in­between outsider and insider. Since the late nineteenth century Wyoming has developed five centers of dude ranch activity located primarily near mountain ranges, within or close to public lands (National Park Service (NPS) or Forest Service (FS)): 1) Medicine Bow Mountain Range in southeastern Wyoming; 2) Big Horn Mountain Range (eastern and western slopes) in north-central Wyoming; 3) eastern gate region of Yellowstone National Park, northwest Wyoming; 4) Wind River Mountain Range (eastern and western slopes), northwestern Wyoming; and 5) Teton Mountain Range in northwestern Wyoming. My work seeks to establish the extent of dude ranching in Teton Valley.

Predicting local biological characteristics in streams: a comparison of landscape classifications

Summary1. Landscape classifications group tracts of land based on similar physico‐chemical attributes that may affect the biological characteristics of streams at local scales. We tested the ability of five landscape models to account for variation in algal and macroinvertebrate biomass, brook trout (Salvelinus fontinalis) growth and macroinvertebrate community composition from 132 riffles in 15 catchments in the Big Horn Mountains, Wyoming.2. A model created by the U.S. Forest Service (FS) combined catchment and ecoregion approaches to classify the landscape. Our model used digital elevations to create a landscape classification for streams (DEM). The last three models were based on: (1) standard ecoregions (Ecoregion), (2) the type of underlying bedrock (Geology) and (3) the geographical distance between sites (Site Proximity model).3. Overall, the Ecoregion and Geology models performed better than the two catchment models (FS and DEM) in predicting local biological characteristics. The Geology model was best at predicting differences in algal and macroinvertebrate biomass, the Site Proximity and Ecoregion models were best at predicting patterns of similarity in macroinvertebrate community composition, and the Site Proximity, Ecoregion, Geology, and FS models, in order from best to worst, accounted for significant variation in brook trout growth. The Site Proximity model performed well because of the effects of spatial autocorrelation. The DEM was consistently one of the worst models at predicting local biological characteristics because it failed to include important attributes (e.g. dominant geology). Calcareous geology was positively associated with greater macroinvertebrate biomass and faster brook trout growth, but it was inversely related to algal biomass.4. None of the models accounted for a large amount of variation in local biological characteristics. Single‐scale, landscape classifications may never accurately predict variation in local biological characteristics because: (1) landscapes show a high degree of spatial heterogeneity, (2) local effects are stronger than landscape attributes and (3) there are too many intervening levels between landscape and local scales in the nested hierarchy of streams. However, landscape classifications did account for significant variation in biological characteristics. Thus, they would be a valuable management tool as part of a multi‐scale, hierarchical technique for classifying stream ecosystems.

Effect of altitude on male parental expenditure in Mountain Bluebirds (Sialia currucoides): are higher-altitude males more attentive fathers?

Male investment of time and energy in caring for offspring varies substantially both between and within bird species. Explaining this variation is of long-standing interest to ornithologists. One factor that may affect male care is breeding site altitude, through its effects on climate. The harsher, less predictable abiotic conditions at higher altitudes are hypothesized to favour increased male investment of time and energy in offspring care. We tested this hypothesis by comparing male parental behaviour in Mountain Bluebirds (Sialia currucoides) nesting at 1500 and 2500 m a.s.l. in the Bighorn Mountains of Wyoming, USA. We compared rates of prey delivery to nestlings at these two altitudes at two times: 1–2 days after hatching, when females spend much of their time brooding young, and 12–13 days later, when brooding has ended and nestling energy demands are peaking. High-altitude males fed nestlings 18 and 28% more often than low-altitude males early and later in the nestling stage, respectively, but only the difference in late-stage feeding rates were significant. Like males, females at the high site also fed nestlings significantly more often than females at the low site later in the nestling stage (45% difference in feeding rates). Consequently, the proportion of all feeding trips made by males at the high site (40%) did not differ significantly from that at the low site (44%). Parents at the high altitude may feed nestlings more often to compensate for their greater thermoregulatory costs. Parents may also be attempting to assist nestlings in storing fat and/or attaining a large size and effective homeothermy as quickly as possible to enhance nestling ability to survive bouts of severe weather which are common at high altitudes.

Combining phylogenetic and ecological niche modeling approaches to determine distribution and historical biogeography of Black Hills mountain snails (Oreohelicidae)

ABSTRACTWe aim to show how a combination of molecular systematics and ecological niche modelling approaches can be used to test historical biogeographical hypotheses for species of conservation concern. We focus on the land snail genus Oreohelix (Oreohelicidae), a group found throughout the Rocky Mountains. In addition to its larger distribution, a group of Oreohelix is also found in the Black Hills of Wyoming and South Dakota, an isolated, easternmost extension of the Rocky Mountains. We determine the number, distribution, and relationships of Black Hills Oreohelicids, which are a current conservation concern due to their fragmented distribution. We compared Black Hills groups to those in the main part of the Rockies to test historical biogeographical patterns that explain current diversity. We collected mtDNA data (COI and 12S sequences) from multiple populations of Oreohelix throughout the Black Hills and in adjacent populations in the Rocky Mountains to construct phylogenetic hypotheses. To determine whether favourable environmental conditions currently exist between the Black Hills and the north‐eastern Rocky Mountains, we used DesktopGARP to generate an ecological niche model for distinct lineages discovered in the molecular phylogenetic analysis. Results show that all Black Hills populations are likely Oreohelix cooperi and that little genetic differentiation exists within this clade. In addition, Black Hills groups are genetically similar or identical to populations found in the Judith Mountains and Bighorn Mountains (north‐eastern Rockies). Ecological niche models show that suitable environmental conditions may exist between eastern Rockies and Black Hills O. cooperi samples. Taken together, the phylogenetic and niche model data, along with the low vagility of the snails, support passive long‐distance dispersal as a likely explanation for current arrangement of biodiversity.

Archean geochronological framework of the Bighorn Mountains, Wyoming

The Bighorn Mountains of the central Wyoming Province expose a large tract of Archean crust that has been tectonically inactive and at relatively high crustal levels since ~2.7 Ga. Seven sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon and titanite age determinations on samples of the main lithologic units provide a geochronological framework for the evolution of this area. The oldest, precisely dated magmatic event occurred at 2950 ± 5 Ma, when diorite to granite dykes and sills intruded an older gneiss complex exposed in the central and southern Bighorn Mountains. Rocks as old as 3.25 Ga may be present in this gneissic basement, as indicated by the oldest dates obtained on areas of zircon grains that are interpreted as inherited cores. A tonalitic gneiss was intruded into the gneiss complex at 2886 ± 5 Ma. Deformation of the central and southern gneisses preceded the intrusion of the Bighorn batholith, a tonalitic to granitic intrusion that occupies the northern portion of the uplift. This composite batholith was intruded over the period 2.86–2.84 Ga. Ca. 3.0–2.8 Ga crust is also present in the Beartooth Mountains, the Washakie block of the northeastern Wind River Range, the Owl Creek Mountains, and the northern Granite Mountains, but late Archean deformation and plutonism has obscured much of the earlier history in the southern portion of this area. The entire area, referred to as the Beartooth–Bighorn Magmatic Zone, has been undeformed since 2.6 Ga. Proterozoic extension was focused in those parts of the Wyoming Province outside of this domain.

Changes in Egg Size and Clutch Size with Elevation in a Wyoming Population of Mountain Bluebirds

AbstractFew studies have examined how avian life-history traits vary within populations as elevation increases and climate becomes more severe. We compared egg and clutch sizes of Mountain Bluebirds (Sialia currucoides) nesting at two elevations (1500 m and 2500 m above sea level) in the Bighorn Mountains of Wyoming over two years. Eggs laid by females at the high-elevation site were, on average, significantly (6%) smaller in volume than eggs laid by their lower-elevation counterparts. Across elevations, egg size showed a significant positive correlation with female body condition (weight relative to size), and high-elevation females had significantly lower indices of condition than low-elevation females. Temperatures during clutch formation were colder at the high-elevation site, and egg size was negatively related to temperature after controlling for the effects of female condition. Clutches of females at high elevations were, on average, marginally smaller (by 5%, 0.3 eggs) than clutches of low-elevation females. Unlike egg size, clutch size was unrelated to either female condition or temperature during clutch formation. This suggests that, when under energetic or nutritional stress at high elevations, females sacrifice egg size before sacrificing clutch size.

CHANGES IN EGG SIZE AND CLUTCH SIZE WITH ELEVATION IN A WYOMING POPULATION OF MOUNTAIN BLUEBIRDS

Abstract Few studies have examined how avian life-history traits vary within populations as elevation increases and climate becomes more severe. We compared egg and clutch sizes of Mountain Bluebirds (Sialia currucoides) nesting at two elevations (1500 m and 2500 m above sea level) in the Bighorn Mountains of Wyoming over two years. Eggs laid by females at the high-elevation site were, on average, significantly (6%) smaller in volume than eggs laid by their lower-elevation counterparts. Across elevations, egg size showed a significant positive correlation with female body condition (weight relative to size), and high-elevation females had significantly lower indices of condition than low-elevation females. Temperatures during clutch formation were colder at the high-elevation site, and egg size was negatively related to temperature after controlling for the effects of female condition. Clutches of females at high elevations were, on average, marginally smaller (by 5%, 0.3 eggs) than clutches of low-elevat...

Rockshelter Archaeology and Geoarchaeology in the Bighorn Mountains, Wyoming

This paper reports on 10 years of research at the Black Mountain Archaeological District, located in north central Wyoming’s Bighorn Mountain range. It focuses specifically on two rockshelters: 48BH1827 (Two Moon Shelter) and 48BH1065 (BA Cave). Two Moon Shelter bears stratified Paleoindian deposits that include a Folsom projectile point fragment, a 10,060 ± 60 B.P. radiocarbon date, and an undated Paleoindian component positioned stratigraphically below the Folsom occupation. Upper levels in the site date to about 8500 B.P. and are associated with the Late Paleoindian Pryor Stemmed complex. BA Cave is a well-stratified and well-dated archaeological deposit yielding cultural occupations spanning the last 4,000 years. Geoarchaeological investigations at BA Cave describe changes in sediment depositional regimes that may reflect significant Late Holocene trends in centennial-to-millennial-scale climatic changes in the Middle Rocky Mountain region. Together, research at these two rockshelters provides a well-rounded picture of prehistoric life and environments in the Northwestern Plains culture area.

Use of a systems-based approach to an environmental health assessment for a waterborne disease outbreak investigation at a snowmobile lodge in Wyoming

Investigations into disease outbreaks generally incorporate an epidemiologic investigation, laboratory analysis, and an environmental health assessment. This last component is designed to discover connections between factors in the environment and the outbreak, but is often limited, either by time and resources, or the expertise of the personnel included in outbreak investigation teams. A waterborne Norovirus outbreak investigation in Sheridan County, Wyoming, in 2001 provides an excellent example of the importance of including an in-depth, systems-based environmental health assessment in outbreak investigations. The epidemiologic component of this investigation identified the water supply of a snowmobile lodge in the Bighorn Mountains as the source of the outbreak, a result that was confirmed by laboratory analysis. Including a systems-based environmental health assessment in this investigation also helped to uncover the underlying environmental factors that led to contamination of the water supply. Those factors included an onsite wastewater disposal system that was overloaded by increased use and not well suited to local soil and geologic conditions and a drinking water system with no treatment or disinfection. In addition, heavy precipitation and increased pumping of wells to satisfy higher demands probably facilitated the contamination of the drinking water wells by causing greater movement of wastewater through the soil and underlying bedrock. By focusing on these links between factors in the environment and adverse health outcomes, the systems-based environmental health assessment also helped to highlight prevention strategies for avoiding recurrences.

Morning Star Dawn: The Powder River Expedition and the Northern Cheyennes, 1876 by Jerome Greene

scenes lead to immanence, how do they square with the moral disciplines ofChristianity, Juda ism, Islam, or Buddhism? Why, indeed, should one read about sacred ground, ifstandingon itis more likelytoproduce personal revelations? O'Connell does not face thesequestions very well. He also leaves out a great countervailing force.The enduring treatmentof landscape in thisregionmay not be thework of poets or art ists,but of engineers. Punching holes through the Cascades, harnessing the Columbia with huge dams, mowing down forests,rising over mountaintops with long-range bombers, tinker ing with nuclear, electronic, and biochemical in ventions ? thishas been the work of thousands of prosperous Northwest residents, a massive effortto obliterate any tutelary spirit of place. To adapt a line from Shakespeare: "How with this rage shall beauty hold a plea, whose action isno strongerthan a flower?" Morning StarDawn: The Powder River Expedition and the Northern Cheyennes, 1876 By JeromeGreene University of Oklahoma Press, Norman, 2003. Illustrations, photographs, maps, notes, bibliography, index. 304 pages. $34.95 cloth. Reviewed by Timothy Lehman RockyMountain College, Billings,Montana On November 25, 1876 ? exactly five months after Gen. George Custer's defeat at theLittleBigHorn? Col. Ranald Mackenzie and eleven hundred soldiers under his com mand attacked a Northern Cheyenne village at Red Fork Canyon on the Powder River in northernWyoming. This dawn attackwas part of theGreat SiouxWar, theU.S. Army's largest military operation since theCivilWar and the lastsignificantIndian resistanceon thenorthern Plains. Afterfightingall day forcontrol of their village, chiefs Morning Star (also known asDull Knife) and Little Wolf led theirpeople awayfrom the soldiers and into the Bighorn Mountains. Bitterwinter cold and near starvationforced the Cheyenne to surrender in the weeks andmonths to come. This storyof themilitary campaign and theCheyennes' defeat is the subject of Je romeGreene's thoroughly researched andwell written monograph. Greene, a research historian fortheNational Park Service, narrates the story of thisparticular event ina largerstruggle with an engaging style,an eyeforrevealingdetail, and a balanced treatmentof all sides. In theaftermathofCuster's defeat, thearmy changed its strategyfordealing with "hostile" Indians on the Plains. At the direction of Lt. Gen. Phil Sheridan and with the full support of army commander Gen.William T. Sherman and theU.S. Congress, the army forced Indians livingat the agencies to give up theirguns and horses, rendering them completely dependent on the army for food and shelter.The army reasoned thatwith their families and friends effectively disarmed and dismounted, theLakota and Cheyenne followersofCrazy Horse and Sit tingBullmight become more cooperative.Those Indians who refused agency controlwere tobe pursued and punished with winter campaigns thatwould put a definitive end to Indian resis tance on the Plains. Greene providesmore detail than thecasual reader might want toknow about thiscampaign, but often these specifics enliven the narrative and illuminate the largerpicture. Through his meticulous attention tomilitary sources we learn, for instance, about the supply lines that were necessary for a winter campaign to be Reviews 161 successful. Hundreds of pounds of grain for horses and tons of food, clothing, and equip ment had to be transported bywagon across a frozen Wyoming landscape. Another example of compelling detail isGreene's description of the "priceless artifacts" (p. 136) that the army cap tured and burned in theCheyenne camp. These included artwork,food supplies, religious items, elaborately decorated clothes, cooking utensils, and a necklace made of human fingers. Equally adept at using both Native Ameri can and army sources,Greene provides insight into all sides of this story.Despite the victory over the Cheyennes, field commander Gen. George Crook remained at thecenterof a storm of controversies. Some military figures charged thathemismanaged the campaign, was insuf ficientlyaggressive inpursuing the Indians, and relied too heavily on Indian allies for scouting and fighting. Greene skillfully recounts the motivations and battlefield activities of three hundred or so Pawnees, Shoshones, and others who enabled the army first to findMorning Star's camp and then todefeat the chief and his followers. Some civilians charged thatCrook's strategyofmaking a surprise attack on a vil lage, killing noncombatants, and destroying pony herds and property caused unnecessary suffering. Morning Star Dawn provides a balanced, factual account thatwill appeal to anyone with a strong interest inmilitary history and Plains Indian warfare. Greene's terse treatment sticks closely to the...

Late Ordovician vertebrates from the Bighorn Mountains of Wyoming, USA

Abstract: Late Ordovician vertebrate faunas occur in clastic sedimentary units along the length of the Rocky Mountains from Colorado to Montana, and across the border into Canada. Most research has, however, been conducted on localities in the southern part of the outcrop belt, particularly the Harding Sandstone Formation of Colorado. Micropalaeontological sampling of the coeval South Piney Member (Winnipeg Formation) in the Bighorn Mountains of Wyoming has revealed an abundant vertebrate fauna. The vertebrate assemblage includes a low‐abundance fauna of 13 conodont taxa that together indicate an undatus Chronozone age (mid‐Mohawkian; mid‐Caradoc; Late Ordovician). The pteraspidomorphs Astraspis desiderata Walcott and Eriptychius americanus Walcott are also present together with one new taxon, Eleochera glossa gen. et sp. nov., which is interpreted as a derived stem‐gnathostome on the basis of its scale histology and morphology. The fauna bears a strong similarity to that of the Harding Sandstone but is of lower diversity. In particular, it lacks the fine‐grained, deeper water component of the Harding Sandstone that contains, inter alia, thelodonts and stem‐chondrichthyans.

New interpretations of the Piney Creek thrust and associated Granite Ridge tear fault, northeastern Bighorn Mountains, Wyoming

The northwest-striking, northeast-directed Piney Creek thrust on the northeastern flank of the Bighorn Mountains in north-central Wyoming is traditionally interpreted as abruptly terminated on the northwest by the transverse Granite Ridge fault zone (new name). The structure of the mountain front north of this fault generally has been described as an unfaulted monocline. However, seismic-reflection, gravity, and borehole data, and the requirement of reasonable shortening balance along the mountain front indicate subsurface continuity of the (buried) Piney Creek thrust northward from the Granite Ridge fault zone—perhaps to the Tongue River lineament near the Montana border. Based on these subsurface data, the Granite Ridge fault is described here as a true tear fault confined to the hanging wall of an uninterrupted, ∼30°-dipping Piney Creek thrust, segmenting hanging-wall thrust displacement between the Piney Creek block on the south and Walker Mountain block on the north. Slip on the Granite Ridge tear fault is expressed at the surface along the eastern margin of the Bighorn Mountains, west of Story, Wyoming, as a resequent fault-line scarp with ∼2000 ft (600 m) of relief, and with ∼3.3 mi (∼5.3 km) of left separation of steeply dipping, Paleozoic rocks. Based on measurement between piercing points produced by the lines of intersection of the steeply, east-dipping Cambrian-Precambrian unconformity with the Piney Creek thrust surface along either side of the Granite Ridge tear fault, a (reverse) left-oblique slip of ∼15,000 ft (∼4500 m) is measured on this tear fault zone. Thus, 30,000 ft (9100 m) of net slip on the Piney Creek thrust in the Piney Creek block decreases to 15,000 ft (4500 m) of net slip in the Walker Mountain block, and slip on the thrust further declines northward. The described Granite Ridge tear fault–Piney Creek thrust geometry may provide a useful model in the investigation of similar fault-offset mountain fronts within the Laramide foreland province of the Middle Rocky Mountains.

Factors Associated with Stocked Cutthroat Trout Populations in High-Mountain Lakes

High-mountain lakes provide important fisheries in the Rocky Mountains; therefore we sought to gain an understanding of the relationships among environmental factors, accessibility to anglers, stocking rates, and features of stocks of cutthroat trout Oncorhynchus clarki in high-mountain lakes of the Bighorn Mountains, Wyoming. We sampled fish with experimental gill nets, measured lake habitat features, and calculated factors affecting angler access among 19 lakes that lacked sufficient natural reproduction to support salmonid fisheries and that were stocked at 1-, 2-, or 4-year intervals with fingerling cutthroat trout. We found that angler accessibility was probably the primary factor affecting stock structure, whereas stocking rates affected the densities of cutthroat trout among lakes. The maximum number of years survived after stocking appeared to have the greatest affect on biomass and population structure. Our findings suggest that control of harvest and manipulation of stocking densities can affect the density, biomass, and structure of cutthroat trout stocks in high-elevation lakes.

The Status, Habitat, and Response to Grazing of Water Vole Populations in the Big Horn Mountains of Wyoming, U.S.A.

Microtus richardsoni, the water vole, was listed as a sensitive species in Region 2 of the USDA Forest Service in 1994. Historical records indicate water voles were found in the Big Horn Mountains, but little was known about their current status. The purpose of this study was to locate water voles in the Big Horn Mountains of Wyoming, develop a habitat profile, and evaluate the extent to which livestock grazing affects them. Accessible creeks with habitat requirements for water voles were surveyed. Water voles were not captured below 2440 m. Grazed and ungrazed sites occupied by water voles were matched and analyzed for percent plant cover, dry weight biomass, riparian classification, mean stream depth, channel type, elevation, precipitation, and temperature. Capture success was significantly greater in ungrazed areas. Percent cover by ferns and thallophytes was significantly greater in areas where water voles were more abundant, and bare ground was significantly greater at grazed locations. Water voles were most abundant on Rosgen B or E streams with a willow/wet Carex riparian class that is found on relatively undisturbed sites with stable, well-developed soils and bank structure. In the Big Horn Mountains, water vole captures were low in comparison to the Beartooth Mountains and synergistic effects of grazing and drying might negatively impact this species.

Laramide exhumation of the Bighorn Mountains, Wyoming: An apatite (U-Th)/He thermochronology study

We report (U-Th)/He apatite ages from the crystalline core of the Bighorn Mountains and compare the exhumation history derived from those ages with the exhumation history determined from sedimentary rocks in the adjacent Powder River and Bighorn basins. Our (U-Th)/He apatite ages range from 62 to 369 Ma and represent a pre-Laramide He partial retention zone that was deformed and uplifted at ca. 65 ′ 5 Ma. The geometry of the He partial retention zone indicates that the basement in the Bighorn Mountains is deformed into a doubly plunging anticline. The preservation of a pre-Laramide partial retention zone in the upper few hundred meters of Precambrian basement indicates that in general, the temperature at the Cambrian unconformity did not exceed the apatite He closure temperature. This is difficult to reconcile with evidence from adjacent basins for thick sequences of sedimentary rocks (3-4 km) prior to 65 Ma, and normal modern geothermal gradients. Either the range was never deeply buried (<2-3 km), its geothermal gradient has been low (<20 °C) since at least the Mesozoic, or our apatites have higher (U-Th)/He closure temperatures (∼80-90 °C) than those measured for other apatites.

The Freshwater Mussel Fauna (Bivalvia: Unionidae) of the Knife River, Minnesota, Following a Rotenone Treatment

ABSTRACT Our objective was to determine if salmonid biomass across a large watershed in the Bighorn Mountains of Wyoming was influenced by stream size, channel slope, or abundance of pool habitat. No relationships were observed with wetted width or channel slope; however, a significant relationship was found between biomass and the abundance of pool habitat. These results suggest that geomorphic stream features had little influence on salmonid biomass, but that instream habitat was important. This pattern may occur in other montane watersheds where streams originate primarily from groundwater sources in limestone formations.

Influence of crystal size on apatite (U–Th)/He thermochronology: an example from the Bighorn Mountains, Wyoming

Near-surface tectonic and geomorphic processes involve cooling of rocks through low temperatures (50–200°C). Because rates of helium diffusion in apatite, titanite, and zircon are sensitive to temperature variations in this range, uranium–thorium/helium thermochronometry ((U–Th)/He dating) is well-suited to establishing the timing and rates of these processes in the geologic record. However, because fractional loss of He is controlled by crystal size such that larger crystals retain a larger fraction of radiogenic He, (U–Th)/He ages must vary not only with thermal history but also with crystal size. Here we present crystal size-correlated He ages from co-existing apatites from the Bighorn Mountains, Wyoming that range from 100 to 350 Ma. These correlations are a sensitive indicator of the rock’s thermal history in a temperature range below the system’s nominal closure temperature ( T c∼70°C for apatite), and are consistent with a thermal history involving residence in the upper 2–3 km of crust since the Precambrian, with maximum temperatures of 65–80°C just prior to Laramide orogenic exhumation. The influence of crystal size on He ages will be most apparent in rocks where temperatures have been in the range of partial He retention for long periods of time (∼30–70°C for >10 7 years). In such cases, accurate interpretation of (U–Th)/He ages must incorporate the effect of crystal size, and this method may provide insights to thermal histories of rocks in previously inaccessible low-temperature ranges.

Molecular markers reveal little genetic differentiation among Aconitum noveboracense and A. columbianum (Ranunculaceae) populations

Aconitum noveboracense, a rare, herbaceous perennial, is restricted to recently unglaciated areas in Iowa, Wisconsin, Ohio, and New York, and federally classified as a threatened species. These populations may be disjuncts of the common congener, A. columbianum Nutt., which occurs in the mountains of the western United States. Morphological characters do not reliably separate these taxa. The identity of Black Hills populations, located between the ranges of the rare and common species, is also uncertain. We characterized genetic variation within and among the Aconitum populations in question using isozymes and randomly amplified polymorphic DNA (RAPDs). Isozymes indicate a high degree of similarity among all populations and a high level of genetic diversity in Black Hills populations. Of 97 scorable RAPD loci, 89.7% are polymorphic and clearly resolve most populations. Like isozymes, RAPDs indicate high levels of genetic diversity in the Black Hills and very strong similarity of these populations to A. columbianum from the Bighorn Mountains. Aconitum noveboracense populations show >80% similarity to A. columbianum populations. A population of A. uncinatum from Ohio shows the greatest differentiation from other populations. Therefore, both isozyme and RAPD data concur with the recent treatment of A. noveboracense and A. columbianum as a single species.

Giving Voice to Place: Three Models for Understanding American Sacred Space

Ten miles east of Bighorn Canyon in northern Wyoming, you start to climb up out of the desert heat toward Medicine Mountain, looming in the distant haze. At this point, Highway 14A begins a torturous seven-mile ascent along a 10 percent grade, rising ever higher into sweet clover and green meadows, spruce trees and lodgepole pines. Staying in first or second gear the whole way up, your engine still overheats by the time you have reached the crest. But, if you follow the small National Forest sign off to the left near the summit and walk another mile and a half after parking the car, you come to what seems to be the top of the world: the Great Medicine Wheel, high in the Big-horn Mountains, an ancient eighty-foot diameter circle of rocks with a cairn in the center and twenty-eight spokes radiating out to the rim.

The Story behind "Fetishes—Medicine Wheel"

Photo The Story behind "FetishesMedicine Wheel" by Mark Olencki The tale started innocendy enough. John Lane, one of my oldest friends, asked if I wanted to go out West to visit a mutual friend and drive to as many national parks as we could manage in a week. I eagerly agreed. It would be my first trip west ofthe Mississippi. We flew into BiUings and headed southeast to Buffalo,Wyoming, where our friend Uved. After spending a few days in that small ranch town, John and I took our rented Chevy into the Big Horn Mountains of northern Wyoming. For a photographer from the South who had only experienced the weathered Appalachians, the rugged peaks of the younger Big Horn Mountains were Uke Ansel Adams prints stretched across the windshield. The lucid quality of western light can only be experienced on a few spring and fall days in South CaroUna. UsuaUy the humidity down South is so high it softens the light and makes many photos have that soft-focus quality ofthe turnof -century Pictorialists. That day as we drove higher into the mountains, every turn brought new vistas and opportunities to bring out my equipment and capture in süver nitrate a bit of the awe I experienced. 199 200Fourth Genre As our first day in the mountains closed, we saw and passed a sign for the Medicine Wheel National Monument. John's topo maps told us we were crossing Medicine Mountain. Quickly we turned around and started up the oneand -a-halfmue gravel road to the site. Halfway up we passed a very unusual site, a NASA observatory like a metallic mushroom on the horizon. How odd I thought, but quickly reasoned, why not? In the middle of nowhere, at 9,000 feet, this mountain would be a perfect place to suck the sky with radar. We found out very soon that ancient peoples had the same idea. Arriving at the crude parking area and gate,John and I assembled our respective equipment. I took several cameras—35mm and 120mm format—and John sUpped his notebooks and pens into a daypack. The Medicine Wheel was stiU a half-müe up a dirt path. With theWheel in sight, and the NASA faculty behind us, the trip departed from the norm. As I walked the narrow ridge path to the MedicineWheel, I could see faces in almost every rock formation! They seemed to be silently watching and guarding the thin ridge that led down from the observatory to what we soon saw was a cloth-covered, fenced circle ofwaist-high rocks. I walked the rock edge where it feU off into what was known as the Five Springs Basin. The sentinels were everywhere. I was struck with the feeUng that we were on holy ground. When we met back up, John admitted that he sensed it too. By this time it was late in the day, and I was privileged to get some of the last of a sunset that had long passed in the vaUey below. I walked around the Wheel with my medium format camera in hand. I didn't shoot much because the Ught was quickly fading and so was my film supply. (I had exhausted most of my film on the faces along the ridge below.) Composition as weU as Ught drew me. I walked around theWheel with my medium format camera in hand. I didn't shoot much because the Ught was quickly fading and so was my film supply. (I had exhausted most of my film on the faces along the ridge below.) Composition as weU as Ught drew me—the simple geometry ofbits ofcloth and bone tied to the fence, the mystery of the Medicine Wheel's ornaments. Fetishes, that was the name given to die objects tied on the fence, a ranger told me later. They had been left as favors, reminders to the spirits during private, individual ceremonies ofdianksgiving and praise that occur there daüy. These fetishes were bits of one's unique and powerful individualism, scraps of T-shirts, bandana remnants, coins, jewelry, and smaU animal skuUs. The faces in the rock and the fetishes tied to the...