Upper Twin Cave
Upper Twin Cave is partially located in Spring Mill State Park with the remainder extending under
private land (some of which is owned by the Indiana Karst Conservancy). The cave is the upstream section
of the Shawnee drainage system (Donaldson/Bronson and Lower Twin caves make up the remaining sections).
The park operates boat tours in their section of the cave from mid-May to the end of October. To
avoid conflicts with the commercial operation, caver access to the Spring Mill SP section of the cave is
available only from November 1 to May 15. Much of the cave has deep pools of water, some of which
requires swimming/floating. The cave can easily flood, so do not enter during high flow, when there is
a chance of significant rain, or during periods of rapid snow melt.
- Proper WNS decontamination protocols must be followed before and after the cave trip.
Both the DNR and IKC will spot check for compliance and groups not following proper procedures will
be denied access and suspended from future trips.
- After the trip, change out of your caving clothes discreetly away from your vehicle. If
impractical, at a minimum remove as much outer clothing as possible before entering your vehicle to change.
Bag and seal everything so as to not contaminate the interior or trunk of your vehicle.
- Properly follow the WNS decontamination protocols to clean your equipment, boots, and clothes when you get home.
- The cave has pooled water, especially in the downstream section and a personal flotation device (PFD) is
- Visiting the Spring Mill State Park section of the cave (even if done from the IKC entrance) requires paying
the park's gate fee (when one is being collected). This should be done by visiting the park's main gate prior
to the trip, even if you plan to park on private land.
- The cave can flood and should not be entered after heavy rains or if there is a forecast for thunderstorms or
snow melt (the Park reserves the right to deny access to any group on the day of the trip, based upon
current or potential weather conditions).
- If you plan to park at the Twin Caves parking lot, park away from the steps down to the cave.
You should have your "after" clothes prepared so they can be retrieved from the vehicle without
contaminating the vehicle.
- All group participants must be at least 16 years old. However, the IKC Access Coordinator has the discretion
to approve exceptions for younger experienced participants.
- Minimum group size is three, maximum is fifteen.
- All group members must have a proper helmet with chin strap, helmet-mounted water-proof light (and backups)
and equipment, and proper clothing for full immersion in 55-degree water (e.g.: a wet suit).
- Please be discreet while on the surface in your caving attire, so as to not encourage other park visitors to
enter the caves. If asked by someone, simply say you have authorization from the park to go in the cave.
- In case of emergency, contact the front gate (or front desk at the Inn, if front gate is unstaffed).
- The trip leader should contact the cave's Access Coordinator [Dave Everton,
DEverton@indiana.edu, 812.272.2300] to discuss the group's
experience level and other qualifications. This contact should typically be at least several weeks in advance
of the proposed trip.
- Each trip participant must complete the on-line WNS Training
Module, print out the form at the end, read and sign the WNS Training Acknowledgement section, and
the DNR Caving Permit section of the form. Preferably, the trip leader will then collect and mail/e-mail
copies of the forms to the Coordinator. All documents must be received by the deadline date given to
the trip coordinator by the Interim Access Coordinator. Anyone not meeting the deadline may forfeit their
opportunity to participate.
- Once all the forms have been received, the Access Coordinator will send back a dated Trip Authorization/Parking
Placard to the trip leader and also send a trip authorization notice to the park staff.
- The trip leader will print out a Trip Authorization/Parking Placard for each vehicle, which will be displayed on
the vehicle's dash while in the cave, so Park staff will know you are an authorized group.
NOTE: The above rules pertain to visiting the portion of the cave under DNR-owned property. Somewhat different
rules/procedures apply when visiting the sections of the cave outside the park via the IKC (fourth) entrance. Please
contact the IKC Upper Twin Cave Patron (also Dave Everton) and visit the
Shawnee Karst Preserve page for more details and permission. IKC permission must be obtained and a separate
liability waiver must also be completed to visit the IKC-owned portion of the cave.
Additional comments if you are visiting Upper Twin Cave via the IKC entrance:
- All visitors traveling downstream must turn around at the marked turn-around point
May 16 to October 31 so as to not interfere with the boat tours or cloud the water. Absolutely no
- If you do have permission for both sections of the cave such that a "through trip" is planned, it is
suggested you enter via the IKC entrance. However, please avoid returning to your vehicle overland by foot. Thus,
either park an "after" vehicle at Twin Cave parking lot in the park and shuttle by car to the IKC
property to start the trip; or plan to retrace your steps back through the cave and exit via the IKC entrance.
- Do not enter or exit the cave via the second or third entrances.