Why is Saskatchewan a pentagon?

[Colophon]

[QUOTE=yabob]
It does jog. Just not by very much (about a mile). Where you want to look is on the western border, just south of rt 90, in Montrose County. Here:

http://www.google.com/maps?q=Bedrock,+CO,+USA&ie=UTF8&om=1&ll=38.201497,-109.007721&spn=0.351274,0.578156&z=11&iwloc=addr

I’ve asked about this one before, in one of the old “state boundary” threads. We suspected it was a surveyor’s error, but no cites.
[/QUOTE]

Well see what the nearest town is – Bedrock! Obviously using Flintstone-era surveying tools

On the topo maps…

northern end of the jog

southern end

Looks like they screwed up around monument no 79.

I wonder if this, and the Saskatchewan jogs, are related to the problems of trying to maintain constant section widths as you progress northwards and the lines of longitude get closer together. That accounts for the periodic jogs in lots of north-south roads, as the surveyors had to readjust the grid.

Edit: and here is a more detailed description of what went wrong.

An 1885 survey found an error of slightly over one mile between mileposts 81and 89 (81 and 89 miles north of Four Corners), and an 1893 survey by the U.S. Coast and Geodetic Survey found a half-mile error between mileposts 100 and 110.

Why didn’t the surveyors change the boundary when they found errors? Once a boundary is marked on the ground and accepted by all interested parties it is a true line even though it doesn’t follow the written description.

A boundary between two states may be changed by agreement of the state legislatures and must be approved by Congress. The Colorado/Utah border stands as surveyed!

[yabob]

Ah, as suspected. Thank you.