Yohogania County, Virginia

Map of Monongalia County in present-day West Virginia and Yohogania County in present-day Virginia; Yohogania County is in light blue.

Yohogania County was created by the new state of Virginia in 1776, in an area long disputed between Virginia and Pennsylvania. The county ceased to exist after the border dispute between the two states was resolved in the 1780s. Thus, it is sometimes referred to as a "lost county," although 1.5 million people live within the territory it once claimed, which encompasses two entire counties and parts of four others in two states.

The problem arose through the complex and conflicting manner of granting territory and defining boundaries during the Colonial period. The North American continent was not surveyed until long after various land grants were made to individual colonies, and such land grants and even governmental entities frequently overlapped.