The Heyrman I site is located in southern Door County. The site produced cultural material from Paleoindian, Archaic, Middle Woodland and Late Woodland times. The archaeological deposits occur in spatially segregated locations. Paleoindian materials recovered from a depth roughly 1.80 meters below the existing ground surface.
Artifacts recovered from the site include Paleoindian chipping debris, a large Archaic ovate biface, a Middle Woodland North Bay type projectile point, and Heins Creek pottery from the Late Woodland period.