Phoenix is a surprisingly easy city to navigate because it is built around a grid system. Roads with names run East and West while streets and avenues run North and South.
As it turns out, it's not just Phoenix that is divided up into a grid, but the whole state of Arizona! How did this system start, and where is the center of the grid? There's an interesting story behind all of this.
In addition to becoming the first President of the United States, General George Washington was also a surveyor. Over the course of his life, he came to own more than 6,500 acres of land (over 10 square miles).
During Washington's time, surveying was a primitive affair. Property lines were measured using imprecise markers such as wooden stakes, rocks, marked trees, streams, and other natural features. This method often resulted in disputes between land owners. Clearly, a better system was needed.
Beginning in 1785, the Continental Congress passed the Land Ordinance which was written by Virginian delegate Thomas Jefferson. He devised a mathematical system for dividing land into squares six miles wide, then further dividing it into smaller and smaller squares. This was the foundation of the Public Land Survey System.
Ohio was the first state to implement the Public Land Survey System starting in 1819. It has been adopted by all of the Western US, including Arizona.
Here's how the Public Land Survey System (PLSS) works: first, an Initial Point must be chosen. From this initial point, two imaginary lines are drawn: one that runs East/West (the Baseline) and another that runs North/South (the Meridian). Now you know the origin of Phoenix's Baseline Road! These lines divide the state into a coordinate plane system, much like the one you may remember from high school Algebra.
Starting from the Initial Point, the state is divided into six-mile sections called Townships, then further divided down into thirty-six one-mile squares called Sections, then into quadrants, parcels, and so forth until the size of a single lot is measured.
When you buy a house in Arizona, the deed to your home will include a paper from the County Land Assessor's Office with the exact township, range, section, and quadrant of your property. This is expressed in a form such as Township 4 North, Range 2 West, Section 4.
The whole state of Arizona is surveyed this way. Every square inch of real estate in Arizona has an exact location using the PLSS. And where does it all begin, you might ask? Arizona's Initial Point is located on top of a small mountain called Monument Hill, where the Salt River meets the Gila River. This hill happens to be located adjacent to Phoenix International Raceway in Avondale, Arizona.
Finding the point of origin has been on my list of things to do for years. I have attempted to locate it once before by driving Baseline Road west until it ended, with no such luck. After some thorough research, I finally learned the location of Monument Hill.
This. Is. It. This is where it all begins. Without this all-important point, Arizonans would not be able to buy and sell land in a fair manner. It has facilitated the growth of Arizona from a sleepy agricultural state to a monument of the Southwest.
The Point of Origin sits on top of a non-descript hill near the racetrack, which draws hundreds of thousands of NASCAR spectators every year, yet few of them stop to admire this important part of our history and our economy.
The Point of Origin is located adjacent to Phoenix International Raceway:
7602 S. Avondale Blvd.
Avondale, AZ 85323
Take I-10 West to Exit 131 (Avondale Boulevard)
Go South on Avondale Blvd. for 6 miles
The parking lot for Monument Hill is immediately to the left of the main entrance, heading back towards the Salt River