The accuracy of county plat maps varies widely. The plat maps accuracy depends on the method used to create the map and the resolution and the scale at which the map was produced.
County plat maps are produced for the purpose of tax assessment and do not represent a survey of real property. Plat maps today are produced using aerial photography, and the photos are used to create a digital map. The resolution and scale for this technique can be highly accurate, within 1 foot; however the accuracy required directly correlates to the cost of producing the maps. This level of accuracy is too expensive for the county plat map's purpose, so county plat maps are usually produced in the most economical manner possible.