Initial Point
The geographic starting point from which all PLSS surveys in a given region originate, established by astronomical observation.
Detailed Definition
An initial point is the precisely determined geographic location that serves as the origin for all Public Land Survey System (PLSS) surveys within a defined region. Its latitude and longitude are fixed by astronomical observations.
Characteristics: - Established through astronomical observation - Marks the intersection of a principal meridian and base line - Serves as the origin for all surveys in its region - Permanently monumented on the ground
Historical establishment: - First initial points established in the early 1800s - Each covers a specific geographic region - 37 principal meridians exist in the contiguous U.S. - Some states have multiple initial points
Examples of initial points: - Willamette Stone (Oregon/Washington) - San Bernardino Meridian Initial Point (California) - Salt Lake Meridian Initial Point (Utah) - Gila and Salt River Meridian Initial Point (Arizona)
Importance: All legal land descriptions within a survey region ultimately reference back to the initial point through the principal meridian and base line system.
Related Terms
PLSS
The Public Land Survey System, a method of subdividing and describing land in the United States using townships, ranges, and sections.
Principal Meridian
A north-south reference line running through an initial point, from which ranges are numbered east and west.
Base Line
An east-west reference line running through an initial point, from which townships are numbered north and south.