THE ALLEN COUNTY LAND BRIEF
Land in the
Clayey High Lime Till Plains setting.
Allen County has 402.5 square miles of land in Ohio. 2 mapped landscape regions meet across Allen County: Clayey High Lime Till Plains, Maumee Lake Plain.
Rolling glacial till plains are interrupted by end moraines and areas of older, more dissected deposits. The historical landscape had more tree cover than the Central Corn Belt to the west.
Regional context: Eastern Corn Belt Plains ↗ · Regional mapping across the county footprint
Where the landscape changes
Allen County intersects 2 mapped regional units. The largest mapped shares are:
- Clayey High Lime Till Plains93.2%
- Maumee Lake Plain6.8%
Huron/Erie Lake Plains in Allen County
A broad former lake plain is interrupted by old beach ridges, dunes and glacial moraines. The landscape is mostly low-relief, with important differences between sandy rises and lower ground.
Read the regional source ↗Finding your parcel within Allen County
The atlas lists 24 cities, towns, townships, and Census communities associated with Allen County, including Marion, Richland, Monroe. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Allen County by land and water
The Census records 4.31 square miles of water within Allen County, or 1.1% of its total area. That share is close to Allen County’s 1.1%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Allen County has 29.6 times the land area of nearby Lima city (13.6 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Auglaize County, Hancock County, Hardin County, Putnam County, Van Wert County within Ohio. A tract near one of these lines should be matched to the county identifier on its own records.

