Tax Map & GIS

What We Do

The Tax Map office is responsible for evaluating all new survey drawings and descriptions, reviewing legal descriptions on any document that transfers property ownership, and assigning all addresses in Knox County. We also maintain and update the County’s GIS data layers and manage all GIS applications.

The Tax Map office archives all survey drawings, addresses, railroad right of way maps, and tax maps (property owner maps) ranging from 1871 to present. Countywide aerial photos are available for several different years. Knox County Road Maps and custom maps are also available. We do not have county plat books for sale; these can instead be obtained at the Knox County Chamber of Commerce.

Survey Review

Parcels with descriptions that do not meet current standards must be surveyed by a Registered Professional Surveyor. Any new boundary survey done in Knox County must be submitted to our office for review and approval. Upon approval, the survey will be filed in survey books or files at the Tax Map office; they are not recorded. New Surveys are reviewed to ensure they meet minimum local and state standards for boundary surveys, such as those provided in the Ohio Administrative Code, Chapter 4733-37.
Click here for details on transfer standards.

Address Assignment

The Map Department assigns all house numbers in Knox County, including the City of Mount Vernon and all villages.
Building a home? Click here for a checklist outlining the steps required to build.
Applying for a house number? Click here for a house number application.
Please note you must have an approved access management permit or driveway permit and the property must be in your name before a house number can be assigned.
For questions, be sure to contact the right office:
If your home is on a County road, contact the Engineers office : 740-397-1590
On a State road? Contact the ODOT Highway Garage: 740-392-3066
For a home on a Township road, contact your township zoning inspector or township house.


GIS stands for Geographic Information System. This form of computerized mapping visualizes geographic information, such as property lines, subdivision boundaries, topography, soil types, aerial photography, and others in individual layers. Map features and layers are linked to a property owner database with information that includes owner names, acreage, and sale price. This is what makes GIS maps “smart” and allows for detailed analyses to that would be almost impossible with hard copy information.

This computerized mapping can be printed out in a variety of scales and paper sizes from our GIS application at need. We provide small page printing on-demand in our office as well as customized mapping for those that are interested in having more than just parcel lines and aerial photos.

Our GIS application is available to the public at two workstations in our office and on the Knox County Auditors website.

Tax Map & GIS

117 East High Street, Suite 131
Mount Vernon, Ohio 43050
Phone: (740) 393-6752
Office Hours
Monday – Friday
8:00 AM – 4:00 PM
Closed weekends and holidays

Justin Smith

GIS Supervisor

Phone: (740) 393-6754

Kim McFadden

GIS Technician

Phone: (740) 393-6752


Thank you for completing the First Responders Residential History ADA Form

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