Maryland Department of Natural Resources

Hogmaw Cave, Washington County

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Dennis Slifer skirting a pool in Hogmaw Cave(photo by Dennis Slifer)
Dennis Slifer skirting a pool in Hogmaw Cave

Five caves are known from the area north of Rohrersville and west of Locust Grove. Two of these – Hogmaw Cave and King Quarry Cave – have several hundred feet of passage and are rather interesting. The remaining three – Column Cave, Keedy Cave, and Rohrersville No. 5 Cave – are small and of little interest. All but the latter occur within 1000 feet of each other and are no doubt genetically related and represent the same original system. Evidence for this is obtained from drainage observations and a surface correlation of the maps.

All five caves occur in the Tomstown Dolomite (dip 25º E., strike N.-S.). The area itself is almost entirely surrounded by metamorphic or igneous rock bodies – Catoctin Metabasalt to the south and west, Antietam Quartzite to the east, and a localized marble to the north, with faulting along the metabasalt contact. The caves are drained by Little Antietam Creek. The major portions of the caves are developed along strike joints, with bedding exerting an influence on passage shape and speleothem occurrence. The general dip is 25º to the east – away from the upthrown fault block of the metabasalt to the west.


The entrance to Hogmaw Cave is south of the King Quarry Cave entrance. Water is encountered in the cave throughout the year, fluctuating as much as three feet, depending on the season. Consequently, it has yielded much of the biological material reported from the system. The cave entrance, which is on the southeastern face of the sink, opens into a short crawlway leading to a small room containing a shallow pool of water. Beyond the pool the cave divides into two passages. The short, right passage ends in a small water-filled room with a siphon.

Dennis Slifer examines speleothems in Hogmaw Cave (photo by Dennis Slifer)
Dennis Slifer examines speleothems in Hogmaw Cave

The second or main passage is a very muddy, Z-shaped crawlway extending for 70 feet. Beyond the narrow crawl, the crawlway becomes a wide channel with ceiling heights from 5 to 8 feet. This passage narrows to the east and leads via a tight squeeze through columns and a near-siphon to a low, broad breakdown room. A tunnel to the north drops 8 feet into a trench containing from 3 to 5 feet of water. Several side passages branch off from this section but become too tight to follow.

Returning to the main passage, we find a route which turns south, by-passing a large, nicely decorated room. The east end of this room is profusely ornamented with columns, white soda straws, small stalactites, and draperies. On the dry, clay floor of this room many interesting invertebrates were collected among decaying nuts and piles of wood which were probably brought into the cave by small mammals. Beyond this room, the muddy passage again opens up into a wide channel. A water-filled crevice, 4 feet wide and 10 feet deep, is encountered approximately 50 feet from the formation room. Persons unknown to the authors have placed a large wood plank across this “well,” giving easy access to the rest of the cave.

An attempt to explore the shelf near the bottom of the pool was made in 1964. With aid of an aqualung, a water-filled passage, 4 feet in diameter, was followed for 30 feet until clouding of the water forced a retreat. No subsequent efforts have been made.

Beyond the crevice and a clay bank, the passage opens into a large, beautifully decorated tunnel, 20 feet wide and 8 feet high. Water one or two feet deep covers the floor of the channel for almost 100 feet. The floor of this passage is solid, presenting no danger to the caver. Beyond this long chamber lies another large room, also with a submerged floor. Many large stalagmites, stalactites, and columns are found in this section. This passage is developed along a major joint with the same orientation as King Quarry Cave. The bedding here, however, is dipping 25º E., and serves to modify passage dimensions and decorations. A long “row” of stalactites and columns occur along a bedding plane intersection and stretches the length of the room. Drapery is developed on the dipping walls and breakdown faces. A stream flows into the rear of this room but the stream channel is too low to negotiate. This last room ends in breakdown, possibly due to blasting in the small quarry nearby which contains the entrance to Rohrersville Column Cave.

For all practical purposes the cave terminates at this point. However, the survey maps show a coincidence of Hogmaw Cave’s southern end (breakdown room) with the small quarry’s northeast face, as well as the overlapping of Column Cave.

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