Gerber Hill Park preserves important remnants of Lenawee County's geologic past. As recently as 15,000 years ago, the area was covered by glacial ice flowing west and northwest out of the Erie Basin. When the ice front retreated eastward, meltwater and runoff collected between the ice to the east and higher ground to the west, ponding into a proglacial lake. Mud and clay accumulated on the flat lake bottom, and sandy beaches formed along the shores. As the ice continued to retreat and lower outlets to the Erie Basin were uncovered, the lake level dropped and exposed the land surface in Lenawee County. Water then pounded the impermeable sediments of the old lake bed, forming what early settlers called the Great Black Swamp, where rich black soils developed into some of the state's richest farmland. Sand left along the former lakeshore remained as a sandy ridge rising above the flat lake plain, though much of it was later mined for construction material or removed to flatten land for agriculture. The park contains remnants of both the proglacial lake bed and the beach, while Gerber Hill is surrounded by flat agricultural plains left by the old lake bed and the swamp that followed it. The swamp and the rich soils it produced first discouraged and later encouraged the settlement of Lenawee County. The site also reflects the county's geologic, historic, and economic past through land donated by Frank and Elizabeth Gerber and their daughters, Frances and Sarah, and through preservation of the property's two sandy ridges, which Frank Gerber wanted kept as a reminder of that past.