Four Corners Monument is indeed off mark

Yes, it's official now, the famous Four Corners monument is indeed off the intended mark, though not as much as previously reported and now in the opposite direction.

The monument is only about 1,800 feet or less off and also in an easterly direction, according to the National Geodetic Survey.

That's instead of the up to 2.5-mile variance to the west, as reported in the Deseret News on Monday.

That's because the premise used to calculate the 2.5-mile difference is wrong.

David Doyle, chief geodetic surveyor for the National Geodetic Survey in Silver Spring, Md., told The Associated Press and other media that he believes the Four Corners marker is off by exactly 1,807.14 feet (0.34 of a mile).

He also said the monument is eastward, not westward of where it should be.

Daniel Winester of the National Geodetic Survey at Table Mountain Gravity Observatory in Longmont, Colo., said while the 2.5-mile marker discrepancy is mathematically correct by today's GPS satellite technology, it fails to take into account that the north-south boundary separating Utah/Colorado and Arizona/New Mexico was never intended to be the 109° west longitude. That was so since Washington, D.C., not Greenwich, was the U.S. survey measuring point when the Four Corners was first identified.

"According to the U.S. Geological Survey Professional Paper 909, 'Boundaries of the United States and the Several States,' page 141, which quotes the statutes of U.S. Congress of 1861 and 1864 which defined the boundaries of then Territory of Colorado and adjacent territories; this north-south line was defined to be 'the thirty-second degree of longitude west from Washington,' " Winester states in an e-mail to the Deseret News.

"And while I am not sure from where in Washington original surveys were conducted, the longitude at the Zero Milestone next to the White House is 77 degrees 02' 11" W. So at most the 'error' is half a mile," he initially estimated.

With the intended, original spot now sizing up to be east, not west of the current monument also means both Utah and Arizona received slightly larger borders from the survey error. Previously the reverse was reported.

Winester notes that the clocks and surveying equipment of that era were not capable of intercontinental surveying. Thus it was not possible to compare to the Greenwich Meridian to determine longitude on a global sense. This was not accomplished until the Trans-Atlantic cable was laid and telegraphic time signals could be sent.