Cave-In-Rock
Also known as: Big Cave; Rock and Cave
Why it's listed
Cave-In-Rock is a natural limestone cave opening onto the Ohio River in Hardin County, Illinois, within the 150-acre state park of the same name. The arched mouth is about fifty-five feet wide, and the cavern runs back roughly 160 feet. Long known as a navigational landmark and as a hideout associated with river pirates, it also played a part in the Civil War. In late 1861, Unionist refugees from Kentucky took shelter in and around the cave, and Brig. Gen. Ulysses S. Grant saw their condition and had them moved to Paducah and Cairo. A Federal camp was in place there by November 29, 1861, and soldiers spent ten days quarrying stone for the defenses at Cairo. The cave also served as the jumping-off point for a Federal raid on Caseyville, Kentucky. These wartime events are the basis for its local significance, with a period of 1861 to 1864.
Significance in brief: The nomination argues the cave is locally significant for Civil War associations. It sheltered Unionist refugees in late 1861, who were seen by Brig. Gen. Ulysses S. Grant and moved to Paducah and Cairo. Stone was quarried nearby for the Federal defenses at Cairo, and the site was the staging point for a Federal raid on Caseyville.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 98000984, listed August 6, 1998. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | 0.5 mi N of the town of Cave-In-Rock, Cave-In-Rock |
|---|---|
| County | Hardin County |
| Listed | August 6, 1998 |
| Reference number | 98000984 |
| Resource type | Site |
| Period of significance | 1861-1864 |
| Architectural style | Other - Natural Cave |
| Criteria |
|
| Areas of significance | Military |
| Level of significance | Local |
| Status (as stated in the nomination) | Part of Cave-In-Rock State Park, used for outdoor recreation; graffiti is regularly cleaned from the cave. |
| Acreage | 0.9 |
| Coordinates | 37.46736, -88.15866 (NPS GIS) |
What listing means for this property
Sites (archaeological sites, battlefields, landscapes) are often listed with a restricted address to protect them from looting or disturbance. Listing is honorary for private owners; federal undertakings on or near the site go through Section 106 review, and state laws may protect burials and artefacts regardless of listing.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 98000984.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5054883
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.