Union Mission Site is a historic site of a church mission and school about 5 miles (8.0 km) northeast of Mazie, Oklahoma.

The school instructed 144 Indian children: 71 Osages, 54 Creeks, and 29 Cherokees; a total of 91 boys and 63 girls.

Epaphras Chapman, which, per the NRHP nomination, is the oldest known monument in Oklahoma.

[2] The site was added to the National Register of Historic Places in 1971.

This article about a property in Oklahoma on the National Register of Historic Places is a stub.