Clemson Island Prehistoric District is a historic archaeological site

Archaeological site

An archaeological site is a place in which evidence of past activity is preserved , and which has been, or may be, investigated using the discipline of archaeology and represents a part of the archaeological record.Beyond this, the definition and geographical extent of a 'site' can vary widely,...

 and national historic district

Historic district (United States)

In the United States, a historic district is a group of buildings, properties, or sites that have been designated by one of several entities on different levels as historically or architecturally significant. Buildings, structures, objects and sites within a historic district are normally divided...

 located at Halifax Township, Dauphin County, Pennsylvania

Dauphin County, Pennsylvania

Dauphin County is a county in the U.S. state of Pennsylvania and is one of the three counties comprising the Harrisburg–Carlisle Metropolitan Statistical Area. As of 2010 census, the population was 268,100. The county includes the city of Harrisburg, which has served as the state capital...

. It is a series of three spatially discrete loci. They constitute a transitional Middle Woodland - Late Woodland mound and associated village, that dates from the Early Archaic period (c. 6,900 B.C.) to the 18th century. The mound was excavated in May and June of 1929.

It was added to the National Register of Historic Places

National Register of Historic Places

The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...

in 1981.