Lancaster County's Hidden Underground
Tucked high on the eastern bank of the Susquehanna River in Lancaster County sits one of Pennsylvania's most remarkable geological oddities: Wind Cave, known locally as Cold Cave. It's not a show cave with paved walkways and gift shops. It's a raw, wild cave system, the largest tectonic cave in Pennsylvania and possibly one of the largest in the eastern United States.
If you're the kind of person who gets excited about crawling through ancient rock fissures in near-freezing temperatures while cave rats watch you from the ledges above, this one's for you.
What Makes Wind Cave Unique
Most caves in Pennsylvania were formed by water dissolving limestone over millions of years. Wind Cave is different. It's a tectonic cave: formed not by water, but by the actual movement and splitting of massive bedrock. The walls of the Susquehanna gorge here are made of ancient Wissahickon schist, an insoluble rock composed largely of mica flakes. When these walls settled and split thousands of years ago, systems of nearly vertical joints opened up, creating an extensive network of underground passageways.
As geologist William B. White noted in the 1959 Speleo Digest, tectonic caves are "formed by actual movement of masses of bedrock." They can occur in any type of rock but are usually found in hard, insoluble formations. With more than a thousand feet of mapped passageways, Wind Cave is by far the largest known tectonic cave in the state. Most others are small. Wind Cave is entirely underground, no open-top chasms here.
There are no stalactites, stalagmites, or other speleothems (cave formations) in Wind Cave. The walls and ceilings are rough throughout, with no evidence of water solution. What you do see: sparkling mica flakes throughout the rock, especially vivid during summer months when condensation washes them clean.
The Temperature: 30 Degrees Year-Round
The cave's dual name tells the story. "Wind" comes from the strong air currents that blow through the main passageways. "Cold" comes from the temperature, a careful check in May 1962 measured 30 degrees Fahrenheit throughout all accessible portions of the cave, with no discernible variation anywhere inside. For reference, most Pennsylvania caves maintain temperatures between 50 and 57 degrees. Wind Cave is dramatically colder.
In warmer months, the temperature difference creates heavy condensation inside. Thousands of water droplets hang from the ceiling and every protruding rock, sparkling in headlamp light like underground jewels, right before they drip down your neck or splash onto your camera lens.
During winter, the cave is dry, but thick sheets of ice form on the walls. The exact winter temperature hasn't been precisely measured, but it's likely even colder than the 30-degree summer reading.
Inside the Cave: Two Entrances and a Maze
Wind Cave has two entrances about 75 feet apart. The main entrance is an almost vertical crack in the rock, 8 feet high and 2 to 3 feet wide. The floor descends gradually into a passageway where the ceiling rises to 15 to 25 feet, running straight under the hill for at least 150 feet. The fractured rock faces characteristic of a geological fault are clearly visible throughout.
About 75 feet in, near a small opening to the surface 28 feet above, a cross joint creates an abrupt right-angle passageway heading south and dropping to a lower level. This connects to the cave's longest section, two or more parallel passageways that make up the bulk of the explorable system.
The passages are a mix of tall canyon-like corridors (good for chimney climbing practice), lower stoopways, and short crawls over breakdown blocks. A 10-foot drop leads to a lower level with numerous offsets and large breakdown. Most leads eventually end in choked tunnels or maddeningly narrow crevices, too tight even for the thinnest explorer, but continuing for unknown distances into the rock.
In 1956, a blasted-open side passage revealed about 100 additional feet of cave. In 1962, another room was discovered, a chamber 12 feet wide, 20 feet long, and up to 17 feet high. The possibilities for finding more cave exist for anyone willing to invest the time to enlarge the narrow crevices.
The cave was mapped in detail in 1967. Download the survey map (PDF), drawn by J. R. Reich, Jr. from a survey by Bernard L. Smeltzer for the Pennsylvania Topographic and Geologic Survey.
The Wildlife: Meet the Cave Rats
Wind Cave's most notable resident is the Allegheny cave rat (Neotoma magister), which nests in certain areas of the cave. These large, curious rodents have been observed here for decades. As naturalist Charles Mohr once wrote: "In Wind Cave I have watched 40 persons file by a ledge where a cave rat sat, seemingly fascinated by the unprecedented parade."
The rats are still there and still inquisitive, though apparently less impressed by spelunkers these days. Interestingly, no other cave fauna, including bats, have ever been reported from Wind Cave, an absence that scientists have noted as worthy of further study. Is it the unusual formation of the cave, or the extreme cold? No one knows for certain.
Important Safety Warning
The property owner requires that only those with proper experience and/or applicable guides enter the caves. You must come prepared with:
- Appropriate clothing for near-freezing temperatures (layers, no cotton)
- Proper safety gear (helmet with headlamp, sturdy boots, gloves)
- A reliable light source with backup
- Experience with wild caving or an experienced guide
It is also strongly advised to notify local first responders before entering in case of an incident. While the cave is described in historical surveys as "reasonably safe" and "easily climbed by the inexperienced," some areas contain potentially dangerous breakdown and the extreme cold poses real risk to unprepared visitors.
This is not a commercial cave with safety railings. Respect the cave, respect the property, and come prepared.
Getting There
Wind Cave is located along the eastern bank of the Susquehanna River in Lancaster County. Access is on private property. Always get permission before visiting. The cave is not a commercial attraction and has no facilities, parking lot, or signage.
More Underground Adventures
If you're interested in caves but prefer a more accessible experience, check out our outdoor activities directory for other adventure options in Lancaster County. For a more family-friendly cave experience, Indian Echo Caverns in nearby Hummelstown offers guided tours through a developed show cave.
Browse our articles for local guides and insider tips, or explore historic sites throughout the county.
Historical Source
Much of the geological information in this article is drawn from Caves of Southeastern Pennsylvania by J.R. Reich, published by the Pennsylvania Bureau of Topographic and Geologic Survey (Harrisburg, Pa., 1974).
