The Holdorf site occupied an upland knoll about three miles north of the Door/Kewaunee County border and was investigated from 1998 through the fall of 2004, with 1,500 square feet hand-excavated. Excavations revealed a complex series of pits and post-molds indicating temporary structures, and artifacts included more than 42,000 pieces of chipped stone and two triangular arrow points. Point style and two radiocarbon dates spanning A.D. 700-1200 suggest use during Late Woodland and Oneota times. Because domestic refuse such as animal bone or pottery was absent, the site was probably not a habitation area but instead a place where nearby groups manufactured and resharpened stone tools. The Christoff site was a small prehistoric campsite on less than one-quarter acre of a steep-sided knoll about one-quarter mile inland from Lake Michigan. Investigated from 1998 through the fall of 2004, it was a rare single-component site representing only one time period. Fourteen hand-excavated units produced a chipped stone biface, chipped stone flakes, and grit-tempered pottery. Radiocarbon dates indicate occupation around A.D. 100 by people of the North Bay culture, who are best known from spring and summer fishing camps along the Door Peninsula coastline; Christoff was likely used instead as a fall inland hunting station.