Geotechnology, Inc. and its exploration team recently helped solve a long-standing mystery about the legendary “lost” English Cave in the City of St. Louis. The cave was closed more than 100 years ago, and many details including its exact location were lost in time. In March 2020, however, the hidden cave was found.
The cave was named after Ezra English, a St. Louis ale brewer who utilized the vast area below ground to store and refrigerate his beer. It is believed to be about 350 feet long, 25-35 feet wide, and about 60 feet deep. In the 1840s it was used as an underground beer garden and entertainment complex. The last recorded use of the cave for commercial purposes was in 1919. After that time, entrances of the cave were sealed and the property above the cave was eventually left vacant.
Descriptions recorded around 1905, led the Benton Park Neighborhood Association to suspect that a large part of the cave was located under their English Cave Community Garden. The Association formed the English Cave Recovery Project which subsequently attracted many supporters throughout the State of Missouri who were interested in the underground landmark.
Two of the most notable financial donors were the Meramec Valley Grotto and the Missouri Speleological Survey. The garden’s actual owner, the Gateway Greening Land Trust, Inc. also endorsed the drill plan.
After many years of planning, the Recovery Project took a major step in substantiating its assumption about the cave’s location and engaged Geotechnology, Inc. to perform the exploration services. For minimal disturbance to the garden and surroundings, Geotechnology, Inc. used a small, low impact drill rig for the project. Relying on limited historical information, the team selected two spots to drill holes deep into the earth below the garden. The team’s first attempt at drilling a nearly five-inch in diameter hole hit limestone bedrock at 16 feet in depth. The effort continued but was soon halted when the core barrel encountered a sand-filled void in the rock. The drill crew cased the hole and continued drilling a 2.75 -inch diameter hole. At a depth of 50 feet, the drilling tools broke through into a void. If the drill location had been two feet to the west, the drill would have remained in the rock wall, but instead, the team had broken through to the English Cave. A second successful hole was drilled southeast of the original boring and reached the top of the cave at a similar depth.
After dropping a laser measurement tool down the hole, a post-doctoral fellow in geological engineering – Ken Boyko – at the Missouri University of Science and Technology used LIDAR (Light Detection and Ranging) scanning to acquire more than 40 million data points and produced virtual images of the vast cavern space.
The confirmation of the English Cave’s location sheds new light on a site that has been hidden for more than 100 years and opens new doors for future explorations, revelations and potential uses.
Established more than 35 years ago, Geotechnology, Inc. is a professional corporation offering a comprehensive range of consulting services in applied earth and environmental sciences. For more information, visit www.geotechnology.com