Over 3,500 acres of the York River was surveyed using acoustic (side scan sonar) and magnetic sensors to locate anomalies that may represent some of the lost fleet from 1781. The Siege of Yorktown was not only fought on land, but on the York River. This important part of our revolution is represented by archaeological remains in the sediments of the river. While a 1978 survey located several sunken ships from the battle, many still have yet to be found. The results of this survey will help guide future fieldwork to determine the locations of those ships and better define the battlefield that helped secure our nation’s independence.

The 2026 Virginia Archaeology Month poster includes a sonar mosaic on the front, which depicts the bottom of the York River as seen through a digital rendering based on the acoustic results of the survey. This mosaic is comprised from hundreds of files and many, many miles of survey lanes. The brighter the color, the more sound was returned to the sensor, indicating a harder bottom texture. The back of the poster shows individual targets ‘seen’ by the acoustic sensor. Paired with magnetic data, this survey resulted in new targets for archaeological divers to investigate.

If you are hosting an event for Archaeology Month, please submit it to our calendar using the form accessed through the button below, or contact DHR Senior Curator Allison Mueller at 804-482-6441. To receive a free copy of this year’s poster, please fill out the form accessed through the button below. To learn about some of the many activities being held during Virginia Archaeology Month, see the event list on this page. The event list will be updated regularly as new information is submitted to DHR.