It's bigger than it should be. Due to an early surveying error, 603,485 acres belonging to NM ended up in Texas.
Too bad. We ain't giving it back! LOL
From the link:
"While the Texas-New Mexico border officially was established by the Compromise of 1850, its precise boundaries were subject to interpretation, the whims of Mother Nature, and – whoops! – simple human error. It turns out that when surveyor John H. Clark in 1859 established the nation’s 103rd meridian as the border between Texas and New Mexico, he accidentally set the boundary about three miles too far west.
The narrow strip of debated land runs along New Mexico’s now-eastern border for 320 miles and encompasses the now-Texas towns of Farwell, Texline, Bledsoe and Bronco.
“That’s our land!” declared officials of the territory of New Mexico, after the error was uncovered during their bid for statehood in 1910. “Don’t even think about it,” replied the state of Texas, which hadn’t been keen about relinquishing slavery or the territory of New Mexico in the first place. “Drop it – or else forget about becoming a state,” Congress told the New Mexicans in 1911.
And so the matter festered for the next 100 years, erupting most recently with a 2005 bill in the New Mexico Senate suing Texas for the land, which died in the legislative process. Two years before, the land commissioners of the two states had proposed to settle the dispute with an old-fashioned duel using antique pistols, followed by a skeet shoot. Fortunately, no modern-day blood was shed, but neither was the issue resolved.
“The exhibit shows that we are still fighting border wars,” said Dr. Frances Levine, director of the New Mexico History Museum. “We don’t always have guns drawn, but our states haggle over political boundaries all the time."