Changing County Borders in Oregon, 1843 - 1941

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THE SHIFTING BORDERS OF CLACKAMAS: Before the settlers created the Provisional Government of 1843 there was no system of records for census or land claims. In the summer of 1843, the Provisional Government divided all of Oregon Country into only four districts: Champoeg, Yamhill, Tuality, and Clackamas with “District Number 3, to be called the Clackamas District comprehending all the territory not included in the other three districts.”  Clackamas District was a vast territory extending east to the crest of the Rocky Mountains and north to the undetermined international border, perhaps at 54° 40' (Russian Alaska). Beginning this year, early Oregon Country settlers regularized their land claims. The next year, 1844, the term "district" became "county" and Clatsop County was created from part of Yamhill. Clackamas County’s borders, in December 1845, moved south to include Butteville (formerly in Champoeg County) and east to the Willamette River, ceding land to Tuality (Washington) County.

The Treaty of London 1846 which set the boundary between British lands and the United States brought drastic change to the County. Clackamas’s northern border went south some 200 miles to be set at the 49th Parallel. With the creation of Washington as a US district in 1853, Clackamas ceded all lands north of the Columbia River. Much of Clackamas’s former (settled) territory is now in Washington State. Two years after Oregon became an official US Territory, the US government dispatched a surveyor who set, in 1851, a Baseline (east to west) and a Meridian (north to south). Clackamas’s eastern border followed a straight line, rather than the Willamette River, so the County now included Oswego (formerly in Tuality/Washington County). In 1854, with the creation of Wasco County, Clackamas’s border moved 450 miles westward to the crest of the Cascade Range rather than the Rockies.

Bitter political battles led to the removal of the Capital from Oregon City to Salem (in 1851) and the creation of Multnomah County in 1856. Clackamas lost its Columbia River front as Multnomah County was carved completely from the northern portion of Clackamas County.

Later border changes were rather minor.  In 1856, Clackamas gained a little territory when the legislature moved the southern border to include Molalla, the north bank of Butte Creek, and the Lower Pudding River area. Wilsonville (formerly in Yamhill County) annexed to Clackamas in 1860. In 1895, two parcels of Sellwood were taken from Multnomah and given to Clackamas. The present border of Clackamas County's northwestern corner (in a stair-step shaped pattern) reflects modern urban annexations. At this spot, Clackamas, Washington, and Multnomah counties all meet and the Portland metropolitan population fills their borders to the very edge.

Maps of the Changed Borders

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Patricia Kohnen