List of principal and guide meridians and base lines of the United States

"Guide Meridian" redirects here. For the highway, see Washington State Route 539.
Figure 1. This BLM map depicts the principal meridians and baselines used for surveying states (colored) in the PLSS.

The following are the principal and guide meridians and base lines of the United States, with the year established and a brief summary of what areas' land surveys are based on each.