Old State Quarry State Preserve

Old State Quarry State Preserve is a former limestone quarry in Johnson County featuring exposed rock walls with visible tool marks from mining work. The site shows distinct geological layers and formations that reveal the natural stone composition of the area.

The quarry began operations in 1842 and supplied limestone for major buildings including the Old Capitol and Iowa State Capitol. Later, it became a research site used by Professor Samuel Calvin for geological teaching and study at the State University of Iowa from 1874 to 1911.

Professor Samuel Calvin utilized the quarry between 1874 and 1911 for geological research and instruction at the State University of Iowa.

The site is small and easy to walk through, covering just a few acres and located near Coralville Lake. Wear sturdy footwear since the rock surfaces are uneven and can become slippery when wet.

This location is the type locality for a specific limestone formation found nowhere else in the region. Geologists and researchers value the site for studying this particular stone formation and its characteristics.

Location: Johnson County

GPS coordinates: 41.76333,-91.57028

Latest update: December 14, 2025 16:42