# When was the last change of a county boundary? **URL:** \ **Category:** Factual Questions\ **Created:** [June 25, 2010, 8:20pm UTC](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523 "2010-06-25T20:20:05Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [June 26, 2010, 10:57am UTC](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523/21 "2010-06-26T10:57:20Z")
> [@TriPolar](#): > > Every time a state border changes in the US, and they do frequently, a county border is changing. Changes occur due to more accurate survey techniques, and boundaries based on changing natural formations. 😉 You were probably more interested in intentional changes, but I’m just in the mood to give an answer like that. Sorry. **TriPolar** actually has a point here. The last time a county – and state – boundary changed iwas a few seconds ago as you read this, in one of those places where the boundary between states A and B is the riverbank, with state A running to the water edge and state B owning the opposite shore and the riverbed. A square inch or two of dirt crumbled off the state-A riverbank, falling into the river – and into state B, and from Historicalfigure County into Indianname County, and shifting the boundary by that few square inches. The latest changes _by legal action_, though, would seem to be what is found at **Captain Amazing** ’s link to the Census Bureau list. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [June 26, 2010, 1:18pm UTC](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523/22 "2010-06-26T13:18:53Z")
There have been several changes to the US-Mexico border along the Rio Grande. The most [recent ones](http://en.wikipedia.org/wiki/Rio_Grande_border_disputes) were in 1970. So presumably the corresponding Texas counties’ borders were changed. ---
**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\ **Post date:** [June 26, 2010, 2:03pm UTC](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523/23 "2010-06-26T14:03:18Z")
As well as the cited “Peconic County” initiative on Long Island, there was also some stirrings to have Brookhaven Township in Suffolk County split off to form, you guessed it, Brookhaven County. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 26, 2010, 2:23pm UTC](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523/24 "2010-06-26T14:23:12Z")
> [@Krokodil](#): > > The last one that involved me was in 1997, when the Montgomery and Prince George’s Counties boundary was moved to place Takoma Park wholly inside Montgomery County. Personally I was against this. Damned Langley Park! ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [June 26, 2010, 4:13pm UTC](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523/25 "2010-06-26T16:13:42Z")
> [@Polycarp](#): > > **TriPolar** actually has a point here. The last time a county – and state – boundary changed iwas a few seconds ago as you read this, in one of those places where the boundary between states A and B is the riverbank, with state A running to the water edge and state B owning the opposite shore and the riverbed. A square inch or two of dirt crumbled off the state-A riverbank, falling into the river – and into state B, and from Historicalfigure County into Indianname County, and shifting the boundary by that few square inches. Does it really change when the riverbed moves? I don’t think so. Othersie then why do so many county and state boundaries remain unchanged on maps even though rivers have shifted? There are plenty of bits of Mississippi and even Illinois that are only accessable from the state across the river, due to river shifts. But the legal boundary didn’t change. Kaskaskia, Illinois is a notable example of a town that’s now WEST of the Mississippi in Illinois. [Previous page](https://boards.straightdope.com/t/when-was-the-last-change-of-a-county-boundary/544523.md?page=1)