Quartzite boulders

Quartzite boulder field


Although Sioux quartzite boulders are found throughout the Glaciated Region, Wabaunsee County in and near Mount Mitchell Heritage Prairie is one of the best places to see them. The boulders are metamorphic rocks—in this case, sandstone that has been transformed through heat, pressure, and chemical changes into quartzite.

Metamorphic rocks are extremely rare at the surface in Kansas, and the Sioux quartzite is not native to the state. All of the boulders, in fact, were carried in by grinding sheets of glacial ice about 600,000 years ago after they were broken off outcrops several hundred miles to the north.

A large field of the Sioux quartzite boulders sits on a hillside on Kansas Highway 99 a few miles north of I-70 in Wabaunsee County. The reddish boulders were likely dumped there as the ice melted and the glacier retreated north. Many of the boulders, also known as glacial erratics, are now stained green by lichen.

Mount Mitchell Heritage Prairie, just northeast of the field, is a good place to see Sioux quartzite boulders up close. Although the boulders there are not as numerous as on the hillside, several are easy to reach on a maintained walking trail, along with outcrops of Permian-age limestone and shale.

The boulder field is on the east side of K-99 approximately four and a half miles north of I-70. Mount Mitchell is about three-quarters of a mile farther north, or about four miles south of Wamego.


Wabaunsee County

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