The Holtz Site, designated 20AN26 is an archaeological site located near Bellaire, Michigan. The site was excavated in 1967 by researchers from Michigan State University. Artifacts found on the site indicate it was a Middle Woodland period encampment, dating to around AD 200-400. It was likely inhabited for a short time by people from southern Michigan who traveled north for a season.
The site was designated a Michigan State Historic Site in 1970 and listed on the National Register of Historic Places in 1973.
- William A. Lovis, Jr. (1971). "Holtz Site (20AN26), Antrim Co., Michigan; a Preliminary Report". The Michigan Archaeologist 17 (2): 49–64.