The Bootlegger’s Sink
In an earlier post, I talked about sinkholes as a geologic hazard. Sinkholes cause damage to property and sometimes lead to that property being condemned. Sinkholes usually aren’t friendly to deal with, but there is a significant, even world-famous case in York County.
Hidden in a small wooden grove among the rolling terrain of the York Valley near Emigsville is a sinkhole that holds some magic. On the property of the York County Fire School on Emig Road in Manchester Township lies Bootlegger’s Sink. The sinkhole is located within the limestone of the Cambrian-aged Kinzers Formation and formed thousands of years ago due to groundwater and surface water erosion. What happened around the 40-foot depression about 8,000 years ago has made the sinkhole famous.
Animals would get too close to the edge of the hole and fall into the cavernous opening. Lying at the bottom of the sinkhole, rainwater running over the limestone would carry dissolved calcium carbonate over the animal remains and started the process of fossilization. As more and more animals fell to their unfortunate deaths and the erosion process continued, a thick bed was developed on the floor of Bootlegger’s Sink.
Before going any further with the fossil story, let’s answer how the sinkhole received its name. It was in the 1940s that the state police were chasing a bank robber across the area. While east of Emigsville, the police ran past the sinkhole, but with other priorities in mind, they first caught the criminal. After arresting the robber, the police returned to the sinkhole to investigate this relatively unknown feature. Upon inspection, police received a bonus when they discovered that an area resident was operating a whiskey still in the bottom of the depression. Thus Bootlegger’s Sink was associated with this location. The story goes that more than one person knew of the whiskey-generating sinkhole overlooking Emigsville.
So back to the important information that really put Bootlegger’s on the map. Cave explorers discovered the fossilized bones at the bottom of the sinkhole, and during the 1960s and early 1970s, members of York Grotto (the local caving club that still exists today) conducted Sunday afternoon excavations at the site. The bone material was carefully collected, mapped, catalogued and sent to Carnegie Museum in Pittsburgh for identification. All of the fauna identified lived during the Pleistocene Period, better known as the Ice Age.
Let’s take you back into time to the Ice Age. York County was never covered by the one-mile ice wall. The glaciers got as close as about 50 miles north of Harrisburg in what we know of today as the anthracite coal fields. During colder periods, the ice might have advanced southward. Warm weather periods, when the glaciers would melt or retreat, are known as “interglacial” periods. There were various advancements and interglacial periods during the Pleistocene, all of which can be precisely dated.
The weather in southeastern Pennsylvania fluctuated with the glacial stages. Fossils found within Bootlegger’s Sink represent both glacial and interglacial periods. Many of the fossils represent those animals that today live in the Hudson Bay area, while others represent those living as far south as North Carolina. Bootlegger’s Sink is one of only five locations in the world where Pleistocene mammal fossils have been recovered, making this site significant.
Below is a list of animals discovered at Bootlegger’s, according to a classic 1966 article written by Guilday, Hamilton and McGrady (Annals of Carnegie Museum, vol. 38, art 8, p. 145-163).
Millipede (2 species) Snail
Salamander Spadefoot toad
American toad Fowler’s toad
Tree frog Leopard frog
Box turtle Worm snake
Black racer Mole snake
Garter snake Rattlesnake
The chart below lists mammals recovered from Bootlegger’s and their chronological distribution.
When the York County Fire School was formed, the association recognized the importance of the site and decided to preserve Bootleggers Sink. Today the sinkhole is under lock and key. Only qualified cavers are allowed to enter, with permission from the fire school.