GeoCorps and the Green Mountain and Finger Lakes Forests

The logo for the GeoCorps, a program of the Geological Society of America.

The Geological Society of America, through the GeoCorps program, strives to increase the number of geoscientists on-the-ground, contributing to the research and protection of geologic resources and developing education and outreach activities. GeoCorps provides temporary geoscience assignments on National Forests and Bureau of Land Management (BLM) lands across the U.S.

The Green Mountain and Finger Lakes National Forest is a proud partner of the GeoCorps program. Find out more about GeoCorps and current program offerings by visiting their website. 



GeoCorps Participant Story

My summer in the Green Mountain National Forest as a GeoCorps Participant: Up Close and Personal with Southern Vermont’s Ponds, Lakes, Streams and Rivers.

The following is a report by 2017 GeoCorps Participant Sophia Larson - Wilderness Water Quality Assessor for the Green Mountain National Forest in Manchester, Vermont.


A young woman poses with the sign for the Lye Brook Wilderness area Green Mountain National Forest

The Author hiking in her GeoCorps project sampling area, the Lye Brook Wilderness, Green Mountain National Forest.


How I Got Here

My first week consisted of long bush-walks through the Vermont wilderness, canoeing through hidden gems of lakes and off-roading up steep mountain slopes. I’m not sure what I was expecting when I began this job, but it was an absolutely thrilling beginning.

I was an Earth Science’s major at Dickinson College, and fell in love with many different disciplines and paths under the large umbrella of Geology. I knew I wanted to get more work experience in the field and lab before deciding on what specific area I wanted to specialize in at graduate school.

I developed my passion for our country’s National Forests and Parks at a young age with my family. We hiked, fished, and explored the natural beauty of these protected areas. My grandfather spent part of his life in the wilderness of Vermont, conducting field research on the reforestation of badly eroded farm lands and the effects of managed cutting of timber in northern forests. Little did I know I would be given the opportunity to conduct research in the same gorgeous areas where he once worked.


My GeoCorps Project


In the spring of 2017, I was hired as a GeoCorps member with the title of Wilderness Water Quality Assessor for the Green Mountain National Forest in Manchester, Vermont. When I received the offer, I was ecstatic thinking about the opportunity to explore the beautiful mountains of southern Vermont, participating in a project that I felt passionate towards and getting a taste of what it would be like working for the National Forest Service. For this study, I would be revisiting and expanding upon the atmospheric and hydrological monitoring of the Lye Brook Wilderness Area to identify and assess trends in water chemistry.

A scientist sits atop a log over a beaver lodge preparing a water sample.

Jim Kellogg (VTDEC Aquatic Biologist) at one of Larson’s sample locations, Little Mud Pond in the GMNF.

This particular project is an extension on the work done in 1980 by the VTDEC. From this previous exploration, for this study we leveraged the monitoring by several biological and chemical parameters that has been performed since 1993 by the Forest Ecosystem Monitoring Cooperative (FEMC) in conjunction with the Green Mountain National Forest. On my team, I was fortunate to have the help and support of my advisors: Angelica Quintana (USFS Soil Scientist), Jim Kellogg (VTDEC Aquatic Biologist) and Scott Wixsom (USFS Biological Technician).



Located in the southern portion of the Green Mountain National Forest, the Lye Brook Wilderness Area (LBW) has some of the highest levels of sulfate deposition and ozone in Vermont. Since 1980, the Vermont Department of Environmental Conservation (VTDEC) has monitored this Class I Wilderness area as well as other lakes near the LBW in order to document the effects of acid deposition on sensitive lakes. A Class I Wilderness area is an area under the Clean Air Act that is designated to be protected more rigorously than national ambient and air quality standards. This region’s high sulfate deposition and ozone levels are attributed to the long-distance transport of atmospheric pollutants.

Within the LBW, waterbodies are primarily located in geologic areas resistant to chemical weathering. Chemical weathering refers to a group of processes that result in the transformation of unstable primary minerals into stable secondary forms when unweathered rock is exposed to variations in temperature, moisture, wind, and other environmental forces (Gaillardet, 2011).

Specifically, five main bedrock formations underly the waterbody sample locations: the Bondville Metadacite and Trondehimte Gneiss formation, Biotite-Granitic Gneiss, the Cheshire Quartzite formation, the Dunham Dolostone formation, and the Cheshire Quartzite formation. Many of the soils in the area were formed from glacial till, and the surficial geology also reflects glacial deposits. We hypothesized that these three contributing factors have a strong effect on the LBW water chemistry, causing very low to negative alkalinity levels and low (~-5) pH levels.


Project Tasks

One of my main responsibilities was to collect four rounds of water samples from 10 sample locations that were an extension of the previous 1980 and 1993 studies. They included brooks, rivers, ponds and lakes within and surrounding the LBW. It involved hiking and driving long distances in all forms of weather, but it was by far the most enjoyable portion of my summer.

A map of of the bedrock geology for the sample site locations int he Lye Brook Wilderness.

A map showing the bedrock geology of the LBW sample.

At each location, change in flow levels, water color, pH, temperature, and conductivity were measured in the field. We collected samples at high water flow periods and low flow periods. Three main analyses were conducted on these field samples; total nitrogen, total phosphorus, and alkalinity. After collecting each round of samples, I delivered them to the Vermont Agricultural and Environmental Laboratory (VAEL) at the University of Vermont (UVM) campus in Burlington.

I also had the opportunity to personally analyze my water samples for Gran Alkalinity at the lab in VTDEC in Montpelier. My advisor, Jim Kellogg, took me through the delicate process step-by-step, to help me collect the most precise measurements possible. I appreciated the time and patience he took to show me this new technique. Learning skills like these are an important part of becoming a knowledgeable and well-rounded earth scientist.

In order to better understand the effects of the geology in my sample area, we conducted an intensive water gradient sample on the Lye Brook River running through the LBW, highlighting a response with elevation and changing bedrock and topography. This process involved GIS analyses and field research, choosing sites with varied underlying bedrock formations, and different elevation and topography. The field work involved a long hike along the Lye Brook River, where I was treated to the beautiful sight of the Lye Brook Falls, a gorgeous waterfall that is a local favorite. Because of all the rainfall this summer, it was often spectacular and roaring with a dazzling rainbow.

Based on all our analyses, we concluded that the low-to-medium buffering capacities of the bedrock geology, surficial geology and soil associations together make the LBW susceptible to surface water acidification, particularly given the observed high atmospheric levels of pollutants.

I was excited to present our findings from this project at the GSA annual meeting in Seattle in October 2017 in a poster presentation. It was a great experience.


Additional Project: Vermont Lay Monitoring Program (Stratton Pond):

Stratton Pond is located on the Appalachian and the Long Trail, at the base of Stratton Mountain in West Wardsboro, Vermont. It is the largest body of water on the Long Trail, and one of the most popular spots for “through” hikers, day visitors and campers to come and enjoy the beautiful landscape. Having spent many long hours hiking for field work this summer, the Stratton Pond trail was by far the busiest trail I experienced.

A scientist analyzes water samples at a table outdoors.

Author processing water samples from Stratton Pond for the VTDEC's Lay Monitoring Program.

I was assigned to be the “lay monitor” of Stratton Pond for the Vermont Lay Monitoring Program (LMP). This program is run by the Vermont Department of Environmental Conservation (VTDEC), and has a cooperative partnership with the USFS to sample Stratton Pond to contribute to their periodic Vermont lake water quality sampling database. Once a week, I would hike into Stratton Pond, board my trusty single person canoe and paddle out to the deepest area of the body of Stratton to sample for the database. I collected water samples which would be tested for total phosphorus (nutrient) concentration, chlorophyll-a (algae) concentration and for water clarity (Secchi disk depth).

These three measurements are indicative of monitoring the health of a pond or lake. Excess phosphorus is the main cause of a lake’s water quality problems. Anthropogenic activity around a lake or pond will increase the amount of phosphorus entering a water body, including fertilizer run-off, failing septic tanks and agriculture runoff. Higher levels of phosphorous entering a water ecosystem will spike algae growth, lowering water quality which can interfere with recreational activities. Excess algae growth falls to the bottom of the lake, causing a buildup of sediments to grow at a rapid rate. An alteration to the ecosystem of a lake to this degree will affect all the environment’s wildlife species in addition to the fish species.

Through the LMP, the VTDEC is able to monitor the health of lakes and ponds across Vermont, analyzing anthropogenic effects of these delicate ecosystems and helping to establish regulations to protect the health of these environments (State of Vermont, 2017). If you would like to read more and see some of the LMP’s data, check out their website.


Take Aways

Working at the Green Mountain National Forest as a GeoCorps member has broadened and fine-tuned my Geology skills. This opportunity allowed me to participate in field work almost entirely on my own, something I was not exposed to in my college studies. I learned a lot about myself, and how to be a better scientist and field researcher. I needed to be extremely organized, allotting enough time for each of my field tasks day to day, and prepared for anything. I developed an even deeper appreciation for nature while getting dirty in the field almost every day, participating in important research that strives to conserve out national protected lands.

A Forest Service employee leans against a sign for the Manchester Ranger Station on a rainy day.

Author in front of the Manchester Ranger Station where she was placed for her GeoCorps internship.

My GeoCorps internship has also helped advance my career path. I feel fortunate to have been a member GeoCorp this summer. I was warmly integrated into the tight-knit USFS community, given endless networking opportunities, resume-boosting skills, and a deeper appreciation for our country’s National Forests.


Work Cited:

Gaillardet, J., Rad, S., Rive, K., Loucat, P., Gorge, C., Allegre, C.J., Lajeunesse, R., 2011.Orography-driven chemical denudation in the Lesser Antilles: Evidence for a new feed-back mechanism stabilizing atmospheric CO 2 . American Journal of Science, v. 300, p.851-894.

“Lay Monitoring Program.” Lay Monitoring Program | Department of Environmental Conservation, State of Vermont, 2017,