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Southern Rockies Pilot Abstract

Western United States Landscape Characterization
Southern Rockies Pilot Study Area, Colorado


The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) is conducting a pilot study in the western United States. This study will advance the science of ecological monitoring and demonstrate techniques for regional-scale assessment of the condition of aquatic resources in the 14 western states in EPA Regions 8, 9, and 10 (shown below). This browser is a demonstration of a versatile communication device for our landscape ecological assessment products, reports, assessments, data studies, and analysis tools.

Image of Pilot Area

Human stresses on the natural resources of the United States are intense. These pressures have resulted in many unintended changes in our ecosystems -- loss of biodiversity, increases in the number of endangered species (e.g. salmon), habitat degradation, and increases in contamination and pollution. Major public and private efforts have gone into controlling pollution, and protecting and restoring natural resources and the ecosystems they depend on. Corrective actions have, and will continue to have, an impact upon how we all lead our lives. We react to the problems that are most visible and thus receive the greatest amount of publicity. To make the most of our environmental efforts, we need to understand and assess the status and trends in the condition of our ecological resources and the stressors affecting these systems. It is not at all clear that we are currently targeting financial resources and/or lifestyle changes on problems or at locations where they will have the most effect.

The landscape component of the Western Pilot Study provides information that has multiple management implications. Regional Landscape products will be provided to assess the spatial distribution of landscape stressors on aquatic ecosystems across each region. This will assist regional managers in understanding how landscape conditions contribute to varying aquatic resource conditions. As such, the products also will contribute to formulation of specific management actions for different geographic locations within each region. The first step in providing regional products will be to test and demonstrate landscape assessment methodologies on sub-regional areas of high importance to each Region. This browser concentrates on the Region 8 pilot area in the Southern Rocky Mountains of Colorado.

Southern Rockies Pilot Study Area

The Western EMAP Southern Rockies Pilot Study Area (SRPSA) is contained completely within the State of Colorado and encompasses a significant and contiguous tract of land in the mountainous portions of the Front Range, South Central, and Southwestern regions of the state. The SRPSA is approximately 56,553 km2 (21,835 mi2) in areal extent and is somewhat triangular in shape. The study area boundary extends from the north-central part of the state at Rocky Mountain National Park (RMNP) southward to a location approximately 40 km (25 mi) north of the New Mexico border, trending west to near the city of Cortez in the southwestern corner of the state and, from there, snaking to the north and the northeast to the RMNP.

The SRPSA is bisected by the Continental Divide and is traversed in the north by Interstate 70 and through its center by US Route 50. Within the study area boundaries are the headwaters, upper reaches, and/or major tributaries of some of the most important rivers of the western United States: the Colorado, South Platte, Arkansas, and Rio Grande. Many of the tallest peaks in Colorado are also found inside the study area, including Mount Elbert which, at 4399 m (14,433 ft), is the highest in the state. The lowest elevations are in high plains/high-elevation rangeland regions of the study area, at approximately 1600 m (5200 ft) above sea level. The average annual precipitation ranges from an approximate low of 380 mm (15 in.) in the lower valleys and rangeland locations and up to 1600 mm (55 in.) or more in the high mountain regions. Geologically, the study area is designated as being a part of the Southern Rocky Mountain Geologic Province. The mountain ranges in it are predominantly north-south trending and are dominated by metamorphic, meta-sedimentary, sedimentary formations and occasional volcanic intrusions. In the higher elevations, past glacial activity has created such landforms as alpine cirques, tarns, glacial moraines, and expansive U-shaped valleys; and in the lower elevations, rocky outcroppings, foothills, hogbacks, parallel ridges, and mesas dominate the landscape.

A significant portion of the land within the SRPSA boundary is administered by the USDA Forest Service, some of which is designated as wilderness area. Ecological habitats of the Southern Rockies include sagebrush shrublands, piņon-juniper woodlands, mountain forests, and alpine tundra. This region is considered an area of biological convergence for fauna and flora, representing the high-elevation/montane environments merging with those of the adjacent, lower-altitude prairie and desert biogeographic zones. As a headwaters region, the SRPSA also contains many species-rich aquatic and riparian ecosystems. Logging, mining, and grazing and other agricultural industries operate in the study area. And, although there are no large metropolitan areas located within the study area boundaries, many internationally renowned ski resorts, such as Aspen, Telluride, Ouray, and Vail reside within it.


Gunnison Basin Biodiversity Project. A Nutshell Natural History

Oregon State University. Oregon Climate Service. Average Annual Precipitation - Colorado. Spatial Climate Analysis Service, 2000.

Southern Rockies Ecosystem Project. The State of the Southern Rockies Ecoregion. http://www.restoretherockies.org/ Exit EPA Disclaimer



EPA - EMAP Home Site Map

EPA - EMAP Western Pilot Study


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