The Willamette Meridian was established in 1851 to survey the territories of Oregon and Washington. The principal base line is the Oregon-Washington border lying in 118 59'10"N latitude. The Willamette Meridian runs from the southern border of Oregon at its southern terminus, and then through Puget Sound in Washington before intersecting the Canadian border at its northern terminus. Ranges are numbered west from the meridian to the Pacific Ocean and east to the Idaho border. Survey townships are run south to north in Washington (above the Willamette Baseline) and north to south in Oregon (below the Willamette Baseline). The initial point of the Willamette base line and meridian lies in a state park a few miles west of downtown Portland, Oregon. The initial point was marked with a stone post in 1885 that is now colloquially referred to as the Willamette Stone.
