Air, Water and Aquatics Header image for the GLEES (Glacier Lakes Ecosystem Experiments Site) - USFS RMRS Air, Water, and Aquatic Environments program

US Forest Service Research and Development

decorative green bar
Rocky Mountain Research Station
 RMRS Science Program Areas
 Air, Water and Aquatics Science Program
 Field Locations
 Contact AWAE
 AWAE Site Map
About the Rocky Mountain Research Station

AWAE Program Headquarters
322 East Front St., Ste 401

Boise, ID 83702

(208) 373-4340


Rocky Mountain Research Station Headquarters

2150 Centre Ave., Bldg A
Fort Collins, CO 80526

(970) 295-5923

United States Department of Agriculture Forest Service.

USDA Link Forest Service Link


Rocky Mountain Research Station Home > Science Program Areas > Air, Water and Aquatics > GLEES (Glacier Lakes Ecosystem Experiments Site)


GLEES (Glacier Lakes Ecosystem Experiments Site)


The Glacier Lakes Ecosystem Experiments Site is a high elevation wilderness-like site where research is conducted to determine the effects of atmospheric change and climate change on alpine and subalpine aquatic and terrestrial ecosystems and the upper treeline ecotone. Long-term physical, chemical, and biological monitoring is an important component of the activities at GLEES.  


Description of the GLEES site: The Glacier Lakes Ecosystem Experiments Site

Other GLEES Pages: Past Publications | Vascular Plant Taxa

This Page Navigation: Site Database | Active Monitoring Programs | Active Research


Relevance to Federal Land Management:


The site has been ideal for developing and testing techniques for monitoring of Air Quality Related Values (AQRVs) in wilderness-type ecosystems.  It is recommended as a research site for evaluation of new questions identified from the Federal Land Managers AQRV Workgroup (FLAG) Phase I Report as research needs to be explored for FLAG Phase II. Intensive research can be conducted without the restrictions imposed on wilderness. The site is accessible in winter by snow machine. The site has relatively light recreation use impact. 


Glacier Lakes Ecosystem Experiments Site


Contact Information


Scientists from universities, other federal agencies, and other research institutions are invited to participate in the research at this site. 

Dr. Robert Musselman - GLEES Manager
USDA Forest Service
Rocky Mountain Research Station
240 West Prospect  Ft. Collins, CO 80526
Phone: (970) 498-1239
FAX: 970-498-1010 or -1212
e-mail: rmusselman[at]




Glacier Lakes Ecosystem Experiments Site location:

  • In the Snowy Range of the Medicine Bow Mountains, 55 km west of Laramie, and 15 km NW of Centennial, Wyoming representative of Class I wilderness areas on public lands.
  • A 600 ha research watershed in complex mountainous terrain at 3200-3500 m elevation.
  • Near the Snowy Range Research Natural Area.
Map of Wyoming showing the Glacier Lakes Ecosystem Experimental Site Location


GLEES Hydrologic, Geologic, Soil, and Floristic characteristics:

  • small, contained alpine/subalpine watershed and subcatchments with interconnected snowfield, first order streams, wetlands and unique glacial cirque lakes.
  • adjacent (120m distant) alpine lakes of similar surface area and depth, but differing in watershed area, inflow patterns (open vs. closed systems), turnover rates, stratification, snowcover, deposition input, water chemistry and aquatic biota.
  • lakes with low buffering capacity, sensitive to atmospheric deposition.
  • ecotone between alpine and subalpine, accessible year round.
  • exposed and slow-weathering bedrock.
  • talus slopes and shallow immature soils having low base saturation.
  • alpine and subalpine vegetation - 304 vascular plant species in 14 distinct forest, meadow, shrub, and krummholz plant associations.
  • old-growth forests with trees > 700 years old.
  • almost 200 phytoplanton species identified.
  • a harsh environment with high winds, low temperatures, and snow cover (and ice covered lakes) 7-8 months each year.


  • Located on the Laramie Ranger District, Medicine Bow National Forest (MBNF).
  • Management similar to wilderness ecosystems with no harvest or off road motorized (except over snow) vehicles allowed. Removed from grazing allotment and mining claims in the 1990's.
  • Research managed by the USDA Forest Service, Rocky Mountain Research Station (RMRS).
  • Close cooperation with MBNF management and RMRS for research dealing with management concerns.
  • Centennial Cabin located 2 km northwest of Centennial, Wyoming, and 10 km from the GLEES, is used for housing and as a staging site for field research. The cabin also houses fully equipped wet and dry laboratories.
  • Relatively close proximity to RMRS headquarters and Colorado State University (2 hrs drive); and the University of Wyoming (1/2 hr drive).
  • A facilities manager and field site manager coordinates field operations at the site.
  • A PC accessible database managed by the field site manager.

The Centennial Cabin is located 1 mile northwest of Centennial, Wyoming.


Site Database

Historic background data:

  • A long history of alpine vegetation research and meteorological monitoring exists at the site and surrounding area. Data were collected here on alpine ecosystems by University of Wyoming ecologists in the 1950's.
  • The Snowy Range Observatory network was established here in the 1960's to collect temperature and precipitation data.
  • A SNOTEL site was established near the GLEES in the 1930's.
  • In the early 1990's the GLEES was part of a monitoring program pairing research sites in the United States with similar sites in Eastern Europe. GLEES was paired with a site on Mt. Elbrus, Russia.

Current data:

  • The GLEES has a rich baseline database of air quality and meteorological data, and an extensive research effort in this ecosystem shown to be sensitive to atmospheric deposition. An extensive collection of meteorological, hydrological, water chemistry, snow chemistry, wet and dry deposition, geological, soils, snow cover, aquatic, floristic, and topographic information exists in the GLEES database.
  • Two major monitoring sites have been established for meteorological and air quality monitoring, one at an alpine/subalpine ecotone location (Glacier Lakes) and the other in the subalpine (Brooklyn Lake).
  • A network of terrestrial field plots, hydrological sites, and permanent vegetation and aquatic sampling plots exists. An extensive herbarium collection of vascular plant species is housed at the Centennial cabin, with a duplicate set archived at the University of Wyoming Herbarium, Laramie, Wyoming.
  • Checklists of terrestrial vascular plant species, phytoplankton, periphyton, zooplankton, and macroinvertebrates have been assembled.
  • The GLEES database is accessible by PC. GLEES data have been used by researchers from other government agencies and universities.

GLEES supports the following monitoring activities:

cloud sun white Meteorological Observations
An 18 meter tower is located at 3286 m elevation between East and West Glacier Lakes. A 30 m tower is located at 3182 m elevation near Brooklyn Lake. A 6 m meterological tower is located near the shore of West Glacier Lake. All three towers support meterological sensors and a datalogger that receives, processes, and stores the data for downloading every Tuesday. Data are captured every 15 minutes and include:
  • Soil Temperature at 0.5 and 20 cm soil depths
  • Surface Wetness
  • Air Temperature
  • Relative Humidity
  • Wind Speed
  • Wind Direction
  • Pyranometer radiation
  • Precipitation

cloud rain white Wet Deposition
As part of the National Atmospheric Deposition Program/National Trends Network (NADP/NTN), precipitation is captured at two sites on GLEES.  One site, WY95 (Brooklyn), is located at the Brooklyn Lake monitoring site, and the second site, WY00 (Snowy Range), is located near West Glacier Lake. A paired comparison of the Brooklyn site was operated 1998-1999 for QA/QC and the site is available for further instrumentation evaluation or comparison.
There are about 200 NADP/NTN stations across the United States, Puerto Rico, and American Samoa. Wet deposition is collected continously at these stations throughout the year, with samples removed between 0900 and 1100 every Tuesday and analyzed locally for pH and conductivity. Samples are then shipped to a central analytical laboratory operated by the Illinois State Water Survey, where they are analyzed for SO4, NO3, Cl, PO4, Na, K, Ca, Mg, NH4, H and reanalyzed for pH and conductivity.
Precipation amounts at the NADP/NTN sites are collected by a Belfort dual traverse recording rain gage, and through utilization of a weight calculation of the sample. NADP data are available from the network, including the two GLEES sites, at:

cloud sun white Dry Deposition
As part of the Clean Air Status and Trends Network (CASTNet), dry deposition and ozone are sampled weekly at the GLEES Brooklyn monitoring site.
Established in 1987, CASTNet comprises 71 monitoring stations across the United States. The majority of the monitoring stations are operated under contract to EPA's Office of Air and Radiation. In conjunction with state and local monitoring efforts, the CASTNet monitoring network is used to determine the effectiveness of emissions control programs.
The CASTNet site at GLEES measures atmospheric concentrations of sulfate, nitrate, ammonium, sulfur dioxide, and nitric acid, continuous ambient ozone levels; and meteorological conditions required for calculating dry deposition rates. The GLEES site is equipped with a temperature controlled shelter, ozone analyzer, meteorological sensors, a filter pack sampling system, datalogger, and a radio phone modem.  Filter packs are exposed for 1-week intervals (i.e., Tuesday to Tuesday) at a flow rate of 3.0 liters per minute and sent to a laboratory in Florida for chemical analysis. Information on CASTNet is available at:

binocular pic Visibility
As part of the Inter-agency Monitoring of Protected Visual Environments (IMPROVE), particulate sampling occurred at the GLEES Brooklyn site since 1993-2004.
The IMPROVE network began collecting data on visual air quality for selected EPA mandatory Class I areas in 1988.  The goals of the program are to: 1) Determine existing visual air quality in federal Class I areas, 2) Identify sources of existing human-induced impairment and 3) Document long-term trends to track progress towards the long-term goal of no human-induced impairment of protected areas. During the 1990's, a camera was located along Highway 130 looking toward the Snowy Range. The GLEES Brooklyn IMPROVE was installed at the GLEES Brooklyn site and began operation in the late 1980's. The GLEES Brooklyn IMPROVE was upgraded to a full IMPROVE site with 4 modules in July 2000, and monitoring was discontinued December 31, 2004. 

IMPROVE particulate data are available at:

EPA Guidelines for visibility monitoring are at:

cloud snow white Snow Quantity and Water Content
The Natural Resources Conservation Service (NRCS) has a SNOTEL site at 3115 m elevation near Brooklyn Lake that remotely samples all precipitation, the minimum, maximum and average temperature, snow depth, and water content. 
A typical SNOTEL remote site consists of measuring devices and sensors, a shelter house with an antenna for the radio telemetry equipment, and solar panels used to keep batteries charged.  A standard sensor configuration includes snow pillows, a storage precipitation gauge, and a temperature sensor.  The snow pillows are envelopes of stainless steel or synthetic rubber containing an antifreeze solution.  As snow accumulates on the pillows, it exerts pressure on the solution.  Automatic measuring devices in the shelter house convert the weight of the snow into an electrical reading of the snow's water equivalent--that is, the actual amount of water in a given volume of snow.
     For more information, see the SNOTEL web site:

cloud snow white Carbon Dioxide Flux Measurements
Ambient atmospheric carbon dioxide, a major contributor to global warming has steadily increased during the past century. Yet, for all of it's importance to radiationally driven atmospheric warming, the global budget of carbon dioxide is still not well known. In an effort to better define the global carbon budget, the AMERIFLUX group has been formed to measure carbon dioxide fluxes using eddy covariance data.
The AMERIFLUX effort is closely coordinated with similar international efforts such as the EUROFLUX. We have established an AMERIFLUX site at GLEES. To support the AMERIFLUX effort, we have installed flux measurements instrumentation on the Brooklyn 30 m tower. Our goal is to obtain flux data at the tower site as nearly continously as possible for the next 5 years. The AMERIFLUX network is described at:



Current Research Activities

Seedling Germination and Survival at the Alpine-subalpine ecotone

     Ecotones are edges of species' distributions, hence they may provide early indications of biological effects of a changing physical and chemical climate.  However, it is not currently known if there is a predictable pattern to dynamic changes in ecotones under natural conditions, in particular, the distribution of seedlings survival.  Plots have been established at GLEES to examine the relationship between patterns of seedling establishment and biotic and abiotic factors at multiple scales (10cm - 25m).  These plots will also be used to follow seedling establishment and survival over time and relate these dynamics to regional climate patterns.

Nitrogen Deposition

     Increasing levels of nitrogen deposition have been reported for the Rocky Mountains, particularly in high elevation alpine watersheds of the Colorado Front Range. Understanding the consequences of increased nitrogen on plant productivity, community structure, and ecosystem function is important to land management decisions in alpine and wilderness areas.  We have experimentally increased nitrogen deposition to small wet and dry subalpine meadow plots and are monitoring ecosystem changes in soil respiration, in soil nitrogen processing, and in aboveground species composition and abundance.

Riparian Hydrology

     High elevation environments in the western United States are sensitive to the effects of anthropogenically derived acidic deposition.  Yet little is known about the movement of these pollutants, such as nitrates, within the hydrological systems of the alpine environments.  The near-stream spatial and temporal gradients of nitrates in the soil solute is the focus of a study.

Nitrogen Cycling in Riparian Ecosystems

    A study is underway to examine the sources and sinks of nitorgen in a subcatchment of GLEES. Isotopic signatures of nitrogen and oxygen will be used to identify sources of nitrate in the system. The research will identify the importance of different landscape types in nitrogen cycling. The study is a cooperative effort of Colorado State University and the RMRS.

The Dynamics of Disturbance on Subalpine Forests

     A study has been being initiated to identify disturbance events and to quantify their relationship to the formation of gaps in the forest canopy of the subalpine forest. A network of plots to examine this question of forest stand dynamics has been established at the GLEES and the nearby Snowy Range Natural Area.

Dendrochronology in the Subalpine Forest at GLEES

     The science of dendrochronology offers a powerful tool to aid in understanding ecosystem processes, especially as influenced by past disturbances, climatic change, and forest growth and development.  Research is developing tree-ring width chronologies and to document maximum age structures in the sub-alpine forest stands in and near GLEES. The age of forest stands at the GLEES has been determined.







Rocky Mountain Research Station - Air, Water and Aquatic Environments Sciences Program
Last Modified:  Tuesday, 13-Oct-2015 11:58:29 CDT

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.