The Preston Monument is the common name for a stone marker at the tri-point (the place where three states meet) of Oklahoma, Colorado, and New Mexico. It is named after Levi S. Preston who surveyed a portion of the New Mexico–Colorado border in 1900.[1] The marker that bears his name was erected by the Bureau of Land Management in 1990.
Preston evaluated and established several monuments during his survey of 1900. He was contracted on October 25, 1899 with the United States General Land Office to survey the eastern New Mexico and western Texas borders and compare his results with prior surveys.
Besides determining the boundaries between Texas and New Mexico, Preston was tasked with determining the true location of (1) the northwest corner of Texas, a point of some contention and believed to be lost, (2) the tri-point of Oklahoma, Texas, and New Mexico some 2 miles to the east, and (3) the tri-point of Colorado, Oklahoma, and New Mexico, some 34 miles north, the tri-point bearing his name.
In 1902, Preston's success in establishing the northwest corner of the State of Texas was published in a bulletin of the U.S. Geological Survey. He was lauded for his "zeal, intelligence, and faithfulness."[2]
Solving the contentious Texas-New Mexico border dispute was not his only legacy. The tri-point monument bearing his name would be called upon in the Supreme Court Case of New Mexico v. Colorado, 267 U.S. 30 (1925) to help establish the permanent border between New Mexico and Colorado.[1]