We’re producing basalt wall stone from an old Northern Pacific ballast quarry about 30 miles north of Yellowstone Park in Paradise Valley.
The basalt flow that has been quarried here is called the Hepburn Mesa Basalt. It erupted about 2.2 million years ago and flowed across river gravels of the ancestral Yellowstone River.
The basalt will be used on a large project in Big Sky, Montana.
About 20,000 years ago a glacier flowing north from Yellowstone overrode the Hepburn Mesa Basalt and left grooves on it’s surface.