The Evansville Metropolitan Grotto is an Internal Organization (grotto) of the National Speleological Society. The purpose of this organization is to promote an active association of individuals who are interested in cave exploration, to cultivate caving skills, to teach and encourage safety, and to promote and demonstrate conservation of the cave environment.

The Evansville Metropolitan Grotto began on May 12, 1960 as The Evansville Museum Grotto of the National Speleological Society with Nan Austin as its first President. Annual dues were $5. At some later date, the grotto became independent of the Evansville Museum and changed its name to The Evansville Metropolitan Grotto of the National Speleological Society. We have operated on a continuous basis since our inception.

Membership is open to anyone who demonstrates an agreement with the purpose of the organization, is at least 16 years of age, and is willing to keep their dues current. Having a good sense of humor is helpful as well (our unofficial name is the "No Slack Grotto"). New members must attend at least one regular meeting, at least two grotto sponsored cave trips, and be approved by a two-thirds vote of the grotto members present at a regular meeting.

All members are encouraged to join the National Speleological Society. All officers must be NSS members.

Membership benefits include a subscription to our newsletter "The Petroglyph" which is published at least twice a year - more often if activity and funds allow. The newsletter is published in both electronic (.PDF) and printed form. Members may elect to receive either or both. The electronic copy includes photographs and graphics in color and saves the grotto printing and mailing expenses.