A cluster of eighteen prehistoric archeological sites within less than one-half square mile constitutes the Indian Hill District located near Newcastle. Indian Hill is the only exclusively prehistoric archeological district yet designated in Nebraska and is listed on theNational Register of Historic Landmarks.
It includes sixteen habitation sites encompassing over thirty individual earthlodge ruins. One site may contain a prehistoric agricultural field. Of the two remaining sites, one is a cemetery and the other is of unknown function. All sites are attributed to the St. Helena Phase, a prehistoric hunting-farming people who occupied northeast Nebraska from A.D. 1100 to 1450.