What is the primary survey line that runs from North to South?

The primary survey line that runs from North to South is the Principal Meridian. In the context of land surveying and mapping in the United States, Principal Meridians are crucial for establishing land boundaries and organizing plots of land within the Public Land Survey System (PLSS). Each Principal Meridian serves as a reference line from which surveys and corresponding townships are measured, with the grid system falling into a north-south alignment.

Understanding this concept is essential for anyone involved in real estate, as it provides a foundational framework for where properties are located in relation to established geographic markers. While the Equator is a line of latitude that runs horizontally, and the Prime Meridian is an east-west line used as a starting point for measuring longitude, it is the Principal Meridian that specifically denotes the North-South orientation within the land surveying context.

The Base Line, on the other hand, is a line of latitude that runs horizontally, intersecting the Principal Meridians to form a grid. This means that while it is important for delineating areas of land, it does not serve the same purpose as the Principal Meridian, which is solely oriented to run north and south. Therefore, the Principal Meridian is the accurate answer to this question.