With the exception of portions of the eastern United States and Texas, the United States is divided into a grid of six-mile squares called Townships and Ranges, commonly known as the rectangular survey system. The Willamette Meridian is one of 37 Principal Meridians in the United States, each of which is named, that define the rectangular survey system.
The Willamette Stone is the "Initial Point" or Point of Beginning of the Willamette Meridian. All land surveys and property descriptions in Oregon and Washington are referenced to this point. Established in 1851 under the direction of John B.