delaware's only cave - Beaver Valley Cave

About Delaware’s Only Cave


Beaver Valley Cave, Delaware’s only cave is now on First State National Historic Park land, which means it’s open to anyone who wants to visit. It’s location is not far from the intersection of Beaver Valley Road and Beaver Dam Road just over the creek and up the hill. Here’s a link to it on Google Maps –   Go check it out! 

A story about Delaware’s only Cave

The State of Delaware has been long known as the only state in the Union without a cave – the “Caveless State”. However, this has proven not true as Delaware DOES have a cave – Beaver Valley Cave!

In 1977, Jack H. Speece documented this unique cave in a paper he presented at that year’s NSS Convention. The following is an edited version of that paper and is presented here with the kind permission of Jack H. Speece.

This paper is copyrighted by Jack H. Speece and is intended for the private use of our audience. Any reproduction of this paper without the consent of Jack H. Speece is prohibited.

The following paper was presented by Jack H. Speece at the History Session of the National Speleological Society Convention in Alpena, Michigan on August 4, 1977.

The Cave of Delaware

A look at Delaware’s geology would be enough to indicate that caves would not be found here. However, a cavity of significance does exist less than 100 feet from the Pennsylvania border. This shelter was used by the Delaware Indians who roamed the Delaware Valley over 200 years ago. Archaeological studies were performed here in the 1940’s. It wasn’t until 1958 that the site became known to the Speleological world. Since that time the cave has been “discovered”, reported and mapped more than any other cave of equal size in the country. It has become important scientifically, historically, speleologically and archaeologically. This cave of Delaware has become a matter of great discussion among caving circles in recent years.

For many years The National Speleological Society listed Delaware as the only state in the Union having no caves. The geology of this area is not conducive to cave formation, but nature has her ways of fooling mankind. Noted speleologists such as William Davies and Henry Douglass had overlooked a landmark in Beaver Valley that many of the locals knew well. Although Indian Rock Shelters had been recorded in numerous historical publications on this area, it wasn’t until 1958 that local resident and caver George F. Jackson reported this geologic feature in the national cave files.(1). Rumors of other caves in the state exist but none have been substantiated. Perhaps a rock shelter or two or an old mine. For example, a cavity has been reported on Gold Hill near Hoopes Reservoir of Wilmington.(2). The void is partially collapsed and the numerous mine shafts in the area make one wonder if the feature is natural or artificial.

Picture a country road winding through a heavily wooded countryside where the trees arch over the drives to form a natural tunnel. The sun sparkles through the voids in the foliage along with small patches of blue sky. A rippling stream gently flows on one side and a rock out-crop forms a bluff on the other. A rustic stonewall runs along and comes up to a narrow humped bridge and in the distance is a large stone farmhouse. This is the quiet, restful sort of place that can be enjoyed by anyone. It is easy to see why the Delaware Indians chose this area as their “retreat” after the work of the spring planting was through. In 1880 the area was a budding community of 300 inhabitants.(3). Today all that remains are a few overgrown foundations and millraces.

Located in the bluff is a cave of speleological importance and although it is only 56 feet long it is of importance to the geologist, speleologist, archaeologist and historian. The large 24-foot-wide, 5-foot-high entrance shelter is only 16 feet deep where it constricts into a 4-foot diameter crawlway sloping 41° upward at a direction of 247°. This passage continues in a rock covered floor in a constricting manner for 22 feet, where it further constricts and bends to the left, pinching out a short distance later (18 feet) in an angled slot.

In 1948 a group of scientists of the Archaeological Society of Delaware participated in an excavation in Beaver Valley (Cave) Rock Shelter. Their efforts are described by Seal T. Brooks in his 1949 Report to the Archaeological Society of Delaware.(4). The 24-foot-wide, 5-foot-high entrance tapers back for a distance of 15 feet. The shelter was covered with scattered stones of all sizes and leaf mold, which covered an uneven layer of dark humus on top of undetermined thickness of yellow clay. Due to the large boulders in the floor, work was performed in the approximately 10 inches of humus. Definite evidence of Indian occupation were found; however, nothing of an unusual nature. Illustrations of these artifacts appear in C. A. Weslanger’s book Red Man on the Brandywine (Wilmington, 1953), page xxii.

The cave is presently owned by the Woodlawn Trustees, Inc. of Wilmington, Delaware, and is patrolled by them. Requests to visit the cave must be cleared in advance by them so the Security Patrol can be notified. There are no plans at this time to develop the area. The property was purchased by them on March 8, 1939, from Alice G, Highfield, who purchased it previously from Paul Leahy.(5)

According to Weslanger, the Delaware Indians established a substantial village in the big bend of the Brandywine close to the Delaware-Pennsylvania boundary during the 1700’s.(6). The village served as home for the annual fish festival for the Indians who would come here after planting their crops.(7). Here the hundred or so families would join in fun and fish the streams for several weeks before returning home to their crops. This was the time of the shad spawning and loggerheads (large marine turtles) were easy to catch. This Unami Delaware village of Queonemysing was connected via a path with an unnamed village on Naaman’s Creek and passed through Beaver Valley and the cave entrance.(4). This was also the way to the Delaware River above Claymont, which was the site of another Indian habitation.(8). Therefore, these people were certainly familiar with the cave and would use it from time to time to seek shelter from the harsh elements of nature.

The rock in which this cave is formed is rather unique to speleology. Its origin is presently under investigation and appears to be a combination of rock slippage, fallen boulders and/or sea action. The Delaware Geological Survey shows the cave in the Wissahickon Schist Formation, a dense micaceous schist, gneiss and migmatite and specifically in the Northeastern facies containing dense garnet granulite and biotite schist.(9). This is probably of Precambrian age composed of igneous and metamorphic rocks of the Glenarm Series. Forney reports that the cave is located in a 50 foot wide and 20 foot high outcropping of hornblende schist which is highly metamorphased.(l0). He further adds that the local rock has been identified on geological maps as mica schist, but in the Survey’s ten samples a ten-power magnifying glass is required to see the crystals.

The schist looks like dark fine-grained granite except that it shows bedding in places the rock has 1 cm. crystals of milky quartz, which were stained brown when the mica (an iron compound) weathered to form rust. In places on the schist are 1/3 cm. crystals of garnet, which is not surprising since garnet mining was performed just across the border in Pennsylvania. The schist has a hardness of 7 and easily scratches glass. In Richard Ward’s report, the cave would be located in Type D Amphibalites.(11). Amphibalites near the gneiss contain calcic plagioclose, hornblende and traces of hypersthene. Those farther away are hypersthene-free, and the plagioclose is replaced in part by epiodate.

The cave files of the National Speleological Society contain numerous reports of this cave. The first is that of George F. Jackson in 1958, which appeared in the Society’s NSS News Volume 16, No. 10, page 99. This report was-followed up in November of 1958 by R. Schweicker and R. Anderson and they produced a Grade 3 survey of the cave and titled it “Cave in Beaver Valley.” This report was also reported in the newsletter of the Northern New Jersey Grotto with the map incorrectly dated November 1959 but named Beaver Valley Cave.(12).

In 1962, Jerry Forney moved into the area and made several investigations. The first of these was dated March 24, 1962 and was of Jewell or Gold Hill Cave.(2). This was highly questioned since mining had been done in the area and a collapse was close to the entrance. A second report on “Delaware’s Largest Cave” was printed in The Philadelphia Grotto Digest in 1963.(9). Extensive research was done by Mr. Forney and the article was reprinted in the National Speleological Society’s Speleodigest for 1963.

In December 1971, John and Jim Buchanan surveyed “Beaver Valley Cave” and submitted a report to the NSS Cave Files. A grade 5 survey was again made by Jack Speece in September of 1972. The latest tape and compass survey was in February 1974 by Phil Winkler and Jeff Kirby. Phil Winkler made his report in the Huntsville Grotto Newsletter as if he was the first to record the feature.(13). A map was not included but was made and filed later. Therefore, it should be safe to say that Beaver Valley Cave is the most reported and surveyed cave of less than 100 feet. It has become a much discussed phenomenon among cavers across the country. Many still remember the reports that Delaware is the only caveless state and find it hard to believe that a unique feature such as this does exist.

The Hagley Museum has a diorama in their main visitors’ center which depicts Indians at the entrance of this cave, one of which is grinding corn. This is to represent Stone Age Industry along the Brandywine and the first “mill” of the area was the Indians’ stone mortar, powered by a woman’s strong arms. The depiction of the cave entrance is authentic.

The cave has been called by many names throughout the ages. It has been referred to by some as Indian Cave due to its historic past. In recent times it has been named Beaver Valley Rock Shelter or Beaver Valley Cave. The latter appears to be the most popular and widely accepted. The cave had also been called Wolf Rock Cave from the outcrop in which it is located. A Revolutionary War legend tells of a miserly farmer who hired two field hands who were British deserters.(10). When the men had almost finished their work, the farmer ran out into the field yelling, “The Redcoats are coming! Run for your lives!” Being deserters, they ran into the cave and hid until nightfall, when they moved on. Another legend tells of one of Washington’s soldiers hiding money in the cave while retreating from the Battle of the Brandywine. Reports also say that the cave was used by the locals during the war to cache their valuables, thus preventing them from falling into the hands of the British soldiers.

It seems amazing that such a small cave would ever deserve a report such as this. Its historical significance and relation to the local folklore, its unique geological formation, its having remained undiscovered by the speleologist until 1958, and its depiction by the Hagley Museum all lead to its fame. Although it is not much to see or explore, its statistics are certainly impressive. Numerous reports have been made by various individuals in an attempt to display its features to the public. The cave of Delaware can no longer be forgotten or disregarded by the scientific world.



(1) Jackson, George F., “Caves in Delaware”, NSS News, Vol. 16, No. 10, p. 99 Oct. 1958

(2) Forney, Jerry, “Jewell or Gold Hill Cave”, NSS Cave Files, March 1962

(3) Industries of Delaware, 1880

(4) Brooks, Seal T., The Beaver Valley Rock Shelter Near Wilmington, Delaware, Bulletin, Archaeological Society of Delaware, Vol. 4 #5, pp 22-24, Jan. 1949

(5) Stocking, John M., personal correspondence with Jack H. Speece, Sept. 14, 1972

(6) Weslanger, C. A., Red Man on the Brandywine, Wilmington, 1953

(7) Dunlap, A. R., & Weslanger, C. A., “Contributions to the Ethno-Histopy of the Delaware Indians on the Brandywine”, Pa. Archaeologist Vol. 30, pp. 18-21, April 1960

(8) Cressan, Hilborn T., “Early Man in the Delaware Valley”, Proceedings of Boston Society of Natural History, Vol. 14, pp. 141-150, May 1889

(9) Geologic Map of the Piedmont Province in New Castle County, Delaware Geological Survey, Bulletin 6

(10) Forney, Jerry, “Delaware’s Largest Cave”, Philadelphia Grotto Digest, Vol. II, No. 7, pp. 47-49, 1963

(11) Ward, Richard F., Petrology and Metamorphism of the Wilmington Complex Delaware, Pennsylvania and Maryland, Bulletin of the Geological Society of America, Vol. 70, pp. 1425-1458, Nov. 1959

(12) Caves of Delaware, Beaver Valley Cave, Speleothemes, Northern New Jersey Grotto, Vol. 7, No. 5, July/Aug, 1959

(13) Winkler, Phil, “Delaware Does Have a Cave”, Huntsville Grotto Newsletter, Vol. 15 No. 2, Feb. 1974

Thanks for reading!

CCCC team