Mexican Cut

Location:   Gunnison County
Size:    420 acres
Designated:   November, 1978
Landowner:  The Nature Conservancy, managed by the Rocky Mountain Biological Laboratory

The first natural area to be designated in Colorado, Mexican Cut is a spectacular glacially carved hanging valley located high in the Elk Mountains.  Alternating layers of limestone and quartzite which have been folded 90° from horizontal and worn differentially by glacial action form a series of shelves, each holding several ponds.  This pond complex is the most important component of the Mexican Cut ecosystem.  The numerous interconnected glacial lakes (tarns) are fed by snowmelt and rainfall.  Although the ponds appear to be subject to similar climatic processes, they often contain distinctly different flora and fauna.  The reproductive biology of populations of the tiger salamander (Ambystoma tigrinum) varies from pond to pond.  Individuals in some populations reproduce while still in a larval form; others reproduce as adults.

Access to this site is strictly controlled, due to the fragility of the ecosystem.  The area is a study site for scientists from the Rocky Mountain Biological Laboratory.   In addition to numerous studies of salamander biology and behavior, other investigations have focused on a variety of aquatic insects and zooplankton, as well as the impact of atmospheric deposition, particularly acid rain.