Yesterday's STL quake was just east of this place. Last April 20, there was a similar suze quake (2.4) just west of this place.

Last year it started draining May 7, 17 days after a quake, and the water showed up on the other side of the river-

Ott wonders if a small-magnitude earthquake reported near Eureka on April 20 shook anything loose. He said that in the early 1990s the lake was always full, but in the past 20 years it hasn’t held water the way it should. “We’ve had people look at it — they couldn’t tell where it was leaking,” he said. “We’ll get someone to look at it in the coming weeks. It is what it is.”

He said the water has drained underground and come up on the Castlewood State Park side in an old creek bed, but the water was not causing issues.

https://www.stltoday.com/lifestyles/sinkhole-partially-drains-lake-at-lone-elk-park-and-not-for-the-first-time/article_ae42c0d7-4f20-560f-9575-c674a9416a9d.html

Prior to the 1940’s, the area served primarily for mining by whatever people were dominate at the time. Before Europeans appeared, the native American people would mine the area’s chert deposits, and trade the high quality material with other tribes. After the 1800’s, the area served as a limestone mine and quarry, generating enough business to start a town, which eventually attracted it’s own railway line. However, the mine played out in 1927, and aside from some planned lumber operation, the land lay fallow.

All this changed when the US was suddenly drawn into World War II. In 1941, the government bought the land under the concept of imminent domain, purchasing over 2600 acres of hilly country pocketed with the remains of shallow mines. It turned the old town and the rest of the space into the Tyson Valley Powder Farm: an ammunition dump, chemical storage center, and weapon test site. The Army built concrete storage shelters, vaults, and several buildings, along with several miles of road, and enclosed all but a few hundred acres of it with a strong, wire fence. Patrols in jeeps carrying machine guns, or on mules with rifles, rode the parameter keeping intruders out.

Much Moar-

https://burningbird.net/tyson-valley-lone-elk-bomb/

Nothing like a little radiation to keep the curiosity tamped down. (Chernobyl anyone?)

You can draw a straight line from Washington University in STL to Fort Leonard Wood army base, and it intersects right through this site.