This data release includes data collected from the Villa Grove helicopter magnetic survey in northern San Luis Valley and Poncha Pass region in south-central Colorado, USA. The survey area extends over the northern part of Great Sand Dunes National Park, Poncha Pass and vicinity, and into the southe

This Laser ablation ICPMS U-Pb detrital zircon data set supports mapping and stratigraphic interpretations of the Upper Devonian Ignacio Formation in southwestern Colorado (Silverton area). All samples were collected from a measured stratigraphic section called "Sultan Creek South" located at 37.710

Geologic mapping, characterization of geologic structures, and sampling for geochronology was completed in two areas of the northwestern Sangre de Cristo mountains from 2011 through 2017. This data release provides the raw analytical data, metadata and sample information for 20 zircon U-Pb age analy

This data release includes data collected from the Villa Grove helicopter magnetic survey in northern San Luis Valley and Poncha Pass region in south-central Colorado, USA. The survey area extends over the northern part of Great Sand Dunes National Park, Poncha Pass and vicinity, and into the southe

Phytophagous insects that deposit eggs directly on hosts confront a plant world of variable quality. Some studies to date provide evidence for positive relationships between the site of oviposition and offspring success, as expected if females choose sites of high quality or if they or their offspri

Previous mark‐recapture studies and population size estimates indicated that in the 1980s populations of the endangered Uncompahgre fritillary ( Boloria acrocnema ) declined precipitously, apparently leading to extirpation at its type locality. This locality and a nearby second site, both high in th

Using the same methods as Britten, my associates and I ran Pollard transects during four flight seasons at Redcloud Peak and during three flight seasons (1991-93) at Mt. Uncompahgre and found that the populations are declining precipitously, genetic analyses show low heterozygosity, and no heroic ef

Sebbene le opere di Harry Gunnison Brown, prese singolarmente, non siano state trascurate in modo particolare, l’insieme della sua produzione scientifica non è ancora stato oggetto di attento esame. Dopo aver collaborate con Irving Fisher al suo volume sul potere d’acquisto della moneta, Brown pubbl

Letter from Dennis Underwood to Chairman George Miller regarding the role of Bureau of Reclamation in Trans-mountain water diversion to the front range of CO. United States Department of the Interior 1990

Diane Lothamer. US DOE. August 14, 1990.

Peggy Dobie. USDA/FS Taylor River and Cebolla Ranger District. December 17, 1990

William J. Nesbitt and Diane Lothamer. OCTOBER 1990