How many principal meridians are there in the rectangular survey system?

• A. One principal meridian called range line
• B. Two principal meridians called range lines
• C. Three principal meridians called baseline lines
• D. Four principal meridians called range lines

Answer: (B)

In the rectangular (Public Land Survey) system, the grid is built from multiple reference lines, not a single fixed one. Each surveying region uses its own principal meridian, a north–south reference line, paired with a baseline, an east–west reference line. Because new lands were surveyed in different areas over time, there isn’t just one or two meridians total—the number varies and there are many principal meridians across the country.

The lines that run north–south and form the vertical divisions of the grid are called range lines, and they run parallel to the corresponding principal meridian. The horizontal divisions are township lines, running parallel to the baseline. This framework creates townships that are six miles on each side, describing land by township and range rather than by a single global meridian.