A Geographer's Scrapbook: A Tripoint by the Side of the Highway

Southwest City, Missouri
October 15, 2016

The AR-MO-OK Tripoint

The location where the boundaries of the states of Arkansas, Missouri, and Oklahoma meet is an easy place to get to. It is next to a highway with three numbers — Oklahoma State Highway 20, Arkansas Highway 43, and Missouri Route 43 — and across from the Corner Stone Station and convenience store.

Since it was easy to get to the tripoint, I will take the easy route in providing some facts about this state tripoint.

This state tripoint was officially established in 1907 when Oklahoma was admitted as a state.
The roots of the future state tripoint go back to the early 1800s when the east-to-west and north-to-south boundary lines were set.
The east-to-west boundary line was established in 1819 when the Arkansas Territory was created, thereby separating it from the Missouri Territory. This boundary was set at 36 degrees 30 minutes, which later became prominent as part of the Missouri Compromise of 1820.
The north-to-south boundary line was established in 1821 when Missouri was admitted as a state. The north end point of this boundary line was set at the mouth of the Kansas River as it enters the Missouri River (known as the Kawsmouth) and proceeded approximately 180 miles directly south to the east-to-west boundary between Missouri and Arkansas where it became the southwest corner of Missouri.
In 1823 a monument stone was set at Missouri's southwest corner. Although the monument is weathered and difficult to read, you can still see "Misr 1823" on its north side and "Ark" on the south side.
The Ozark Culture Club in 1915 memorialized the tripoint by constructing a concrete cuboid on the spot. The 1823 monument was placed in the center of the top of the cuboid.
The local Lion's Club refurbished the tripoint in 1955 by adding a concrete pedestal and a circular concrete skirt surrounding the tripoint. The skirt shows the state boundaries as they meet at the tripoint with figures of the states in their right location.