The Four Corners monument is apparently off by 2 1/2 miles. The initial survey that established the borders of those states in 1868 was off. It would seem that all the maps would be off too, in that case. If that’s true, I would imagine the bigger story is probably that some folks who believed they lived in one state will now find out they live in another.
I imagine this is going to have implications for water rights, considering the San Juan river now is going through states it wasn’t originally thought to be going through. There’s an old saying in the west that whiskey is for drinking and water is for fightin’. If this survey is correct, I would say Arizona, New Mexico, Colorado and Utah are going to be fighting for some time.
UPDATE: Actual location of the border is centered on this map here. There’s going to be a lot of people affected. Several towns.
UPDATE: Looks like the controlling law here was the Arizona Organic Act of 1863.
That all that part of the present Territory of New Mexico situate west of a line running due south from the point where the southwest corner of the Territory of Colorado joins the territory of New Mexico.
There would then have to be an act declaring what the border between Colorado and New Mexico territories was supposed to be. I’ll see if I can find that.
UPDATE: Yep. Congress passed “An Act to provide a termporary Government for the Territory of Colorado” passed in 1861:
That all that part of the territory of the United States included within the following limits, viz: commencing on the thirty-seventh parallel of north latitude, where the twenty-fifth meridian of longitude west from Washington crosses the same; thence north on said meridian to the forty-first parallel of north latitude; thence along and parallel west to the thirty-second meridian of longitude west from Washington; thence south on said meridian to the northern line of New Mexico; thence along the thirty-seventh parallel of north latitude to the place of beginning, be and the same is hereby erected into a temporary government by the name of the Territory of Colorado.
Washington is located at 77 longitude west, so that would indeed put the southwest corner of the Colorado Territory at 109 longitude west.  Hell, even Google Earth says it’s off. Looks like Arizona and Utah just got more territory, and New Mexico and Colorado will lose some. Of course, I don’t doubt this matter will go to court, and be settled there, but from a cartological point of view, the border seems to be wrong.
UPDATE: Very interesting Wikipedia entry on public land surveys.

