A congregation of 2,000 people, composed of Native Americans, trappers, and traders from the region, attended the service.

The service was one of the earliest Christian religious ceremonies conducted in the Rocky Mountain region.

[3] The Prairie Mass Site lies approximately at the confluence of the Green River and its tributary Horse Creek.

Mass is facilitated by the parish Our Lady of Peace located in Pinedale, WY.

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