When property lines run through the front door

Could make for some interesting mortgage re-fi's if your land may not really be yours.

That sounds like beach front property in Texas where the beach is public property. The shore line shifts around after every storm. Houses end up either in the surf or on the beach and not behind the dunes where they should be. People should know this when they buy a beach front house in Texas.

FAULT

Steely Dan bump
(My Old School)

Public officials in the East Bay have tried to stay out of the disputes,

Feed from the trough, but do nothing in return. Fire the bums.

landowners own a geographic area,

I thought surveys were done with respect to local "monuments". When I sold my last house, the monuments were two concrete posts buried at the time the carrot farm was subdivided into home lots in the 1960's. If the monuments move you may have a set of inconsistent monuments, I don't know how the law handles this, it certainly does not come up very often in this part of the country.

Prior to differential GPS, it would have been impractical to define lots with respect to geodetic points, i. e., latitude and longitude. As late as the 1890's the geodetic location of most astronomical observatories (including Greenwich's latitude) was uncertain to tens of meters - scores of feet.)

Of course, there is one clear legal precedent:

In The Great Landslide Case, Mark Twain told a story about a practical joke played on a newly arrived U.S. Attorney for the territory of Nevada. The fictitious case devised by the local citizens involved two ranching neighbors who disputed claims to the same piece of property. It seems that a rancher named Mr. Morgan lived on a steep mountainside uphill from a fellow rancher, Mr. Hyde. Well, a terrible landslide transported Morgan's ranch - all of it - downslope and onto the exact area occupied by Hyde's place, covering it "to a depth of about thirty-eight feet." Mr. Hyde was able to escape the horrible event. When he returned to the site of his interred ranch he discovered a happy Morgan, who refused to leave, laying claim to his newly placed cabin, fences, cattle, and barns. He said he was just occupying what was his, and "he's going to keep it - likes it bettr'n he did when it was higher up the hill."

Lawyers were engaged on both sides of the complaint, the U.S. Attorney taking Mr. Hyde's case. The judge listened to an onslaught of witnesses who overwhelmingly supported the side of Hyde.

What was the verdict? The judge, who was part of the ruse, conceded that although the bulk of evidence favored Mr. Hyde, he ruled... "Heaven, in its inscrutable wisdom, has seen fit to move this defendant's ranch for a purpose. We are but creatures, and we must submit. If Heaven has chosen to favor the defendant Morgan in this marked and wonderful manner; and if Heaven, dissatisfied with the position of the Morgan ranch upon the mountainside, has chosen to remove it to a position more eligible and more advantageous to the owner, it ill becomes us, insects as we are, to question the legality of the act or inquire into the reasons that prompted it. No - Heaven created the ranches, and it is Heaven's prerogative to rearrange them, to experiment with them, to shift them around at its pleasure. It is for us to submit, without repining... Gentlemen, it is the verdict of this court that the plaintiff, Richard Hyde, has been deprived of his ranch by the visitation of God! And from this decision there is no appeal."

Hyde's lawyer, incensed at the foolish verdict, visited the judge that same night to negotiate a modification of the verdict. After pacing the floor and pondering for more than two hours, the judge smiled and told the lawyer that " Hyde's title to his land underneath Morgan's was still as good as it had ever has been... and therefore he was of the opinion that Hyde had a right to dig out from under there and..."

The U.S. Attorney "never waited to hear the end of it. He was always an impatient and irascible man, that way. At the end of two months the fact that he had been played upon with a joke had managed to bore itself, like another Hoosac Tunnel, through the solid adamant of his understanding."

- from Samuel L. Clemens, Roughing It: The Great Landslide Case

When I look at a map, it looks like the town stays in the original state, even if the river moves. The interstate boundary has weird curves and curls that bear no resemblance to the current river course. So you can walk from Mississippi to Arkansas and back again without ever getting your feet wet!