Imperial in Jefferson County, Missouri — The American Midwest (Upper Plains)
Quarry Operations
A journey back through time
Photographed by Cajun Scrambler, July 29, 2021
1. Quarry Operations Marker
The rock face before you is not the natural bluff face. In 1905, the Union Sand and Material Company of St. Louis operated a lime plant here. Three quarries exist within the park; you are standing in the largest one. A smaller one exists at the base of the bluff, and the third resides along the Limestone Hill Trail.
At the top of the quarry face is the edge of the original land surface. You are standing on a working surface about 35 feet below. Kimmswick Limestone is approximately 400 million old. The rock, a crystalline grey limestone, is used in making cement and building stone.
Evidence of the former quarry operations is visible on the bone bed below. Brick fragments, concrete slabs, and building remnants scatter along the short trail. The trail leading up from the bone bed is the old roadbed to the four-story high quarry. Vegetation in the area today has grown up in the last 75 years after being clear cut during the quarry operations.
Erected by Missouri State Parks.
Topics. This historical marker is listed in these topic lists: Industry & Commerce • Natural Features • Natural Resources • Parks & Recreational Areas. A significant historical year for this entry is 1905.
Location. 38° 22.721′ N, 90°
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Regionally, this marker is in the Missouri River Corridor and in Greater St. Louis. It is also in the American Midwest, in the Lewis & Clark Corridor, in the Corn Belt, and in the Great River Road Region. Globally, it is in North America, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once the territory of the Mississippian Culture, the Louisiana Purchase, and the Antebellum South.
Other nearby markers. At least 8 other markers are within 3 miles of this marker, measured as the crow flies: Kimmswick Bone Bed (within shouting distance of this marker); Excavating the Bones (within shouting distance of this marker); Bring Us Home (approx. 0.9 miles away); Flame of Freedom (approx. 0.9 miles away); El Camino Real (approx. 1.3 miles away); Windsor Harbor Road Bridge (approx. 1½ miles away); Kimmswick Historic Flooding (approx. 1½ miles away); Welcome to Sulphur Springs Landing (approx. 3 miles away). Touch for a list and map of all markers in Imperial.
More about this marker. Located in the Mastodon State Park of Missouri on the "Wildflower Trail". Rugged terrain but the trail is an easy/moderate hike. Lots of stairways to get to this site. Hiking trails are free, admission charged for the museum area.
Photographed by Cajun Scrambler, July 29, 2021
2. Quarry Operations Marker
Photographed by Garrett Koch, August 1, 2023
3. Quarry Operations evidence
These steel plates secured into a concrete foundation at the site are remnants of the quarry work being done at this site through the years after 1905.
Credits. This page was last revised on August 30, 2025. It was originally submitted on August 13, 2021, by Cajun Scrambler of Assumption, Louisiana. This page has been viewed 848 times since then and 75 times this year. Photos: 1, 2. submitted on August 13, 2021, by Cajun Scrambler of Assumption, Louisiana. 3. submitted on August 25, 2025, by Garrett Koch of Saint Louis, Missouri.
