Wisconsin Geological Society

Trilobites are extinct arthropods
              that form the class Trilobita. They appeared in the Early
              Cambrian period and flourished throughout the lower
              Paleozoic era before beginning a drawn-out decline to
              extinction when, during the Late Devonian extinction, all
              trilobite orders, with the sole exception of Proetida,
              died out. The last of the trilobites disappeared in the
              mass extinction at the end of the Permian about 250
              million years ago

Welcome to the official website of The Wisconsin Geological Society, Inc. (WGS), founded in 1936. The Wisconsin Geological Society, Inc. (WGS) offers a variety of ways to increase understanding of our planet. The purpose of WGS is to create an interest in the study of geology; to provide the means for the development of knowledge in geology; and to disseminate information concerning all phases of geology.

The Wisconsin Geological Society, Inc (WGS) is a member of the Midwest Federation of Mineralogical and Geological Studies (MWF) which is a part of the American Federation of Mineralogical Societies (AFMS)

Membership meeting of WGS: 2nd Monday of each month, September-June

7:00 Business meeting.  7:30PM Program/Show and Tell

WGS Junior Rockhounds Meeting: 6:30 pm

Meetings held at the Immaculate Heart of Mary Church, (South end, Hall, downstairs),

1212 So. 117Th St., West Allis, WI, 53214

Thank you to everyone that came to the 2015 Gem, Mineral, and Fossil show.
Wisconsin State Fossil:
The Wisconsin Geological Society proposed a state fossil in 1985 to encourage interest in our geological heritage. The trilobite (pronounced "TRY-low-bite") is an extinct marine arthropod that was common in the warm, shallow salt sea that periodically covered Wisconsin hundreds of millions of years ago.


  • Respect private and public property.
  • Always get permission when collecting on private land.
  • Follow current government regulations when collecting on public land.
  • Before collecting make sure you find out any restrictions for the type of collecting that you can do ( surface only, hand equipment, etc. ) and any limitations of quantities.
  • Leave the area in the same or better condition than you found it in when you arrived.