Geology, Hydrology, Ecology


Some 1.6 million to 10,000 years ago, the Rocky Mountains in Wyoming were covered by large glaciers which carved montains, carried boulders miles from their places of origin and created the topography known today as the Wind River Range.  In this era, termed the Pleistocene, several glaciations occurred in Wyoming and were named after the locations where the glaciation evidence was first noted.  So, the Bull Lake Glaciation (approximately 140,000 years ago) was named for Bull Lake, Wyoming and the Pinedale Glaciation (approximately 30,000 years ago) was named for the Town of Pinedale, WY, near the foot of the terminal moraine. Approximately 700 to 150 years ago, a period of glacier advances and retreats occurred and was termed the "Little Ice Age". 

The boulders, rocks and other stone debris carried by the ice and left behind as the ice melted and retreated formed ridges termed moraines.  Moraines can be terminal moraines, occurring at the toe of the glacier, or lateral moraines, formed alongside the glaciers.  Recessional moraines occur when the glaciers advance and retreat, in a pulse like manner, dropping lesser quantities of rocks each time and forming a series of ridges. Medial moraines are formed when two glaciers move in the same direction but side by side.  When they merge in an action similar to the confluence of creeks or rivers, the rocks and boulders left behind are parallel to the glaciers movement. Moraines mark the edge of the glacier advance and are a visible sign of the glaciers movements and spread.

Moraines can be used as evidence of glacier melting and thinning.  In other words, a moraine shows where the glacier was in a previous time and the height of the glacial ice.  When the glacier melted, the boulders, rocks and other materials it carried were left in place.


Wyoming and Switzerland have a lot more in common than mountains.  Both have large concentrations of glaciers in remote regions and both contain the headwaters of major river systems.  Wyoming glacial meltwater contributes to the Missouri River, the Mississippi River, the Green/Colorado River and the Snake/Columbia River.  Switzerland is the headwaters of the Rhine River, the Rhone River, the Inn/Danube River and the Po River.  In essence, while Wyoming is the rooftop of the United States of America, Switzerland is the rooftop of Europe.  These respective glaciers and their contributions to downstream water users cannot be underestimated.  Millions of people depend on the life giving waters which originate in Wyoming and Switzerland.

Wyoming has an estimated 80 glaciers with 63 of these in the Wind River Range, the largest concentration of glaciers in America's Rocky Mountains.  A recent study completed by in 2009 by University of Wyoming researchers found that glaciers in the Wind River Range had decreased approximately 25% in the period from 1985 to 2005. (Kyle S. Cheesbrough Masters Thesis:  This warming phenomena is also occurring in Wyoming's Yellowstone Park, a UNESCO World Heritage Site, as warmer waters in the Firehole River killed over 1,000 trout, a cold water fish, in 2007.  The event caused the US National Park Service (NPS) to close 232 miles of Yellowstone Park rivers to fishing in order to reduce stress on trout.

As glaciers melt and shrink, smaller glaciers provide less hydrologic buffering capacity. Large glaciers have enough mass to delay the melt of their winter snowfall covering so the snow and ice melts later in the year and provides water flows during late summer. Smaller glaciers can't cool the overlying layer of snow and as a consequence, snow melt occurs earlier in the season and runs off at higher flows. 


Temperature and precipitation changes have strong impacts on the ecology and the evolution of alpine organisms, their distribution patterns, community composition and ecosystem functioning.  Macroinvetebrates, insects large enough to be seen with the naked eye and not having a backbone or exoskelton, have evolved through the millenia in adaption to their environments.  As climatic changes occur in rapid succession, ecosystem functioning will be impacted - - the main question is how and to what extent?

To predict how alpine ecosystems are affected by climate change, inter-continental research is being conducted to gain a better understanding of the relative roles played by landscape processes.  These include abiotic (not having a biological living component, e.g. rock), biotic (having a biological living component, e.g. soil, river) processes and ecological processes. 

Both Wyoming and Switzerland offer a natural laboratory to study the responses of aquatic alpine macro-invetebrates in the functioning of their rapidly changing ecosystem.  The sensitivity of alpine macroinveterbrates to environmental change, their ease of monitoring, the existing research base and historical records make these well suited for studies of responses to climate change.