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Fraser Experimental Forest

Scientist in Charge: 

General Description

Established in 1937 by the Forest Service, the Fraser Experimental Forest comprises 23,000 acres. This outdoor research laboratory was first established to study the relationship between forest management and water yield. Today, the Fraser Experimental Forest is a site for research on silviculture, riparian habitats, invasives, insects, soils, and other topics, in addition to water quantity and quality.

Check out the Fraser Experimental Forest Brochure for more information.

Background Information and History

Mountain pine beetle outbreak on the Fraser Experimental Forest, 2007.
Mountain pine beetle outbreak on the Fraser Experimental Forest, 2007.
The Fraser Experimental Forest lies in the heart of the central Rocky Mountains, roughly 50 air miles west of Denver, Colorado. The Forest Service established the Fraser Experimental Forest in 1937 to study the relationship between forest management and water yield in the subalpine zone. Comprising 23,000 acres, this outdoor research laboratory is an ideal location to study water, forests, and other physical and biological processes, and their integration in high-elevation subalpine watersheds. Today, the primary research addresses questions that deal with water quantity and water quality, and their relationship to forest vegetation and management across a range of scales from the small plot, to the hillslope, and basin. Other contemporary research projects include silviculture, riparian habitats, sediment, invasives, insects, soils, climate, birds, and a number of other pertinent topics.


Collins, Byron J. ; Rhoades, Charles C. ; Hubbard, Robert M. ; Battaglia, Mike A. , 2011
Rhoades, Charles C. ; Elder, Kelly J. ; Greene, E. , 2010
Elder, Kelly J. ; Cline, Don ; Liston, Glen E. ; Armstrong, Richard , 2009
Hardy, Janet ; Davis, Robert ; Koh, Yeohoon ; Cline, Don ; Elder, Kelly J. ; Armstrong, Richard ; Marshall, Hans-Peter ; Painter, Thomas ; Saint-Martin, Gilles Castres ; DeRoo, Roger ; Sarabandi, Kamal ; Graf, Tobias ; Koike, Toshio ; McDonald, Kyle , 2008
Hubbard, Robert M. ; Ryan, Michael G. ; Elder, Kelly J. ; Rhoades, Charles C. , 2005
Shepperd, Wayne D. ; Asherin, Lance A. ; Mata, Stephen A. ; McClain, Douglas L. , 2004
Brown, Peter M. ; Shepperd, Wayne D. ; Brown, Christopher C. ; Mata, Stephen A. ; McClain, Douglas L. , 1995
Popovich, Steve J. ; Shepperd, Wayne D. ; Reichert, Donald W. ; Cone, Michael A. , 1993
Alexander, Robert R. ; Troendle, Charles A. ; Kaufmann, Merrill R. ; Shepperd, Wayne D. ; Crouch, Glenn L. ; Watkins, Ross K. , 1985
Alexander, Robert R. ; Watkins, Ross K. , 1977

Ecological Information

Fraser Experimental Forest is the source of St. Louis Creek, a northeast-facing basin that is a tributary of the Fraser River. The Fraser River joins the Colorado River near Granby, about 20 miles north of the town of Fraser.


Climate varies strongly with elevation and aspect; snow increases and temperatures decrease with elevation. Elevation varies from 8,792 to 12,795 feet (2,680 to 3,900 m), and about one-third of the forest is above timberline at 10,990 feet (3,350 m). The climate is generally cool and humid, with long, cold winters and short, cool summers. Average annual temperature at Forest headquarters at 9,000 feet (2,745 m) is 32 °F (0.5 °C), and snowfall and frost can occur any month of the year. At Forest headquarters, mean monthly temperature for January is 14 °F (-10 °C) and for July, 54 °F (12.7 °C). Annual precipitation at Forest headquarters averages 23 inches (584 mm) (range 17 to 28 in, 430 to 710 mm), Average annual precipitation over the entire Experimental Forest is 29 inches (737 mm). Nearly two thirds of the precipitation falls as snow from October to May.


Soils generally come from gneiss and schist. Typical soils contain angular gravel and stone with very little silt and clay. These soils are very permeable, and can store considerable water during snowmelt. At high elevations, especially on the west side, soils come from sandstones. These soils are shallow, have large amounts of stone, and have fine sand or sand textures. Alluvial soils occur along main streams, and are made of a mixture of glacial till, glacial outwash, and recent valley fill.

Vegetation Types

The St. Louis watershed includes subalpine forests and alpine tundra typical of the central Rocky Mountains. In the forested areas below timberline, Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) are predominant trees at higher elevations, on north-facing slopes, and along streams. Lodgepole pine (Pinus contorta var. latifolia) is the predominant tree at lower elevations and on drier, south-facing upper slopes. The majority of the forest began growing, sometimes slowly, after a stand-replacing fire in 1685. Pockets of older trees grow in riparian areas and at higher elevations. The flat, low elevation portion of the forest was logged in the early 1900s. Researchers and managers have used additional treatments to reduce fuels and conduct research over the last decade.


Elk, deer, moose, black bears, and mountain lions are the forest's big animals. Elk mostly live in the alpine grassland and high cirque basins in the summer, but winter outside the forest. Mule deer are more common than elk. In the summer, they graze in the timbered areas and openings of the forest. In the winter, they move to the lower areas. Moose live in Fraser year round. Black bears, unlike the elk and deer, are very shy, and rarely seen. Mountain lions are occasional visitors. Many small, furred animals live in Fraser, such as marten, mink, badger, musk rats, red and gray fox, coyote, bobcat, lynx, and beaver. Beaver live along the water courses. Snowshoe hares, pine squirrels, mice, gophers, shrews, and voles also live in Fraser. Numerous game and non-game birds live throughout the forest. Trout live in some streams, beaver ponds, and lakes.

Research – Historical and Present

The primary research focus for Fraser has been the effect of management practices on water yield and quality. Researchers collect snow depth and water content on four gauged watersheds, with records dating to 1941 for one watershed. Early research at Fraser Experimental Forest focused on timber, water, and sediment produced by forest management practices. For this research, many long-term study plots were established in both lodgepole pine and Engelmann spruce, and four watersheds were monitored for streamflow and weather. Some of the records now exceed 60 years in length. Biogeochemical studies began in the 1960s were restarted in the 1970s, and have been continuous since 1982. Other studies focused on how forest species and structure affected snow distribution, water use, and water yield.

Research Accomplishments

Research at Fraser has provided significant advances in our understanding of subalpine forest ecology and hydrology, as well as many of the silvicultural and hydrological practices used in forest management.

Long-term Monitoring and Data

Long-term research at Fraser continues to build on the data and records collected over the last seven decades. Fraser is one of the only research sites in the Rocky Mountains that maintains long-term records on temperature, precipitation, streamflow, snow depth, forest structure and growth, and responses to forest management. Fraser is unique among these sites in providing catchments that span alpine to lower subalpine ecosystems, with a full suite of site histories and environments (ages, aspects, elevations). It enables researchers to perform whole-ecosystem manipulations in watersheds that are representative of high-elevation watersheds of southern and central Rockies.

Facilities Information

A road network to Fraser includes a public access, main-stem dirt road that follows St. Louis Creek, and controlled access roads in Fool Creek and West St. Louis Creek. The St. Louis Creek road is closed at the Denver Water diversion. Access may be permitted on controlled roads for approved research projects with a demonstrated need.

The Fraser Experimental Forest Headquarters facility includes a 12-room dormitory, kitchen, and bath facility. The facility is currently open for year-round use.

An on-site laboratory is available for use by approved collaborators, and has limited analytical capabilities. Space is available for instrumentation provided by collaborators for specific projects.

Driving Directions to the Fraser Experimental Forest from Denver:

  • Take I-70 west to US-40, exit 232, for Empire, Winter Park, Granby. 
  • Continue 30 miles over Berthoud Pass and through Winter park to Fraser (all on US-40).
  • Turn left on County Rd. 72 (at the first stoplight). (Safeway is on your right at the stoplight.)
  • Continue straight for 0.3 miles. The road turns to dirt and goes under a cement railroad bridge.
  • The road forks on the other side of the bridge. Take a right (Fraser Valley Parkway) and follow this road to the first stop sign (0.8 miles).
  • Take a left onto County Rd. 73, which is temporarily paved. Continue 4.4 miles.
  • Climb the hill and continue, without any major turns, to a group of buildings on your right. You will pass several residences, one campground, and several junctions. Stay on the most direct route – the least turns possible.
  • These buildings are the Fraser headquarters.  Please check in at the office, which is the first building on your left as you enter the headquarters area.

Research Opportunities

The Experimental Forest network encourages re-use of the data collected by its members. We recognize the importance to our participating scientists of receiving proper credit for the contribution their data make to other projects. It is also important to both our scientists and to Forest Service Research & Development that we understand who is using the Experimental Forest Network data. The scientists use this information in their performance reviews; Forest Service Research & Development uses it to guide decisions on allocation of resources (for example, web-based access to data, re-packaging of Data Products for particular audiences, etc.) and for its performance review with Congress. Therefore, most Experimental Forest Network research data are covered by a data use agreement. If you are familiar with the Long Term Ecological Research network, you will notice that this agreement has been modeled on their agreement. Please note that the Network does not judge the quality or appropriateness of the data you use.

If you have conducted a research study on this Experimental Forest, we would be interested in helping you make these data available to the scientific community and the public. We are available to help with data set preparation and metadata development.

Benefits to archiving data through the R&D Data Archive:

  1. Long-term preservation of data; and
  2. Assignment of a Digital Object Identifier (DOI), which can be used to track data usage.

Please contact Kelly Elder for more information.

National Priority Research Areas: 
Climate Change; Watershed Management and Restoration