One Mile South Dakota / Montana border?

If you go to your atlas and look at the western snake of the state of South Dakota where it borders Montana, you will see a straight flash with a kink of almost one mile. Everywhere else the border is a straight line. The kink does not benefit any local landowner, and no other states are involved. Why is the kink here?

Can anyone help solve this? I'm truly stumped.



Answers:   
The kink if truth be told exists at the meeting of South Dakota, Montana, and Wyoming. The Wyoming and North Dakota borders are around 1 mile different, meaning the western South Dakota border needed to be corrected by 1 mile. I'm not sure if be the result of a different parallel being used for respectively state or if there be a deeper meaning at the time South Dakota be created.
it could be a river or an old dried out hose down way
if the queue is blue it is a waterway


Related Questions:
Where is a moral place to snow sled within WA state?   We're MOVING?!?   Do Las Vegas or LA enjoy any bed surrounded by breakfast ?   South Chicago suburbs?   Is June a well brought-up time to walk to Walt Disney World surrounded by Florida?  
  • When visit Boston for 4 days, would you recommend the Go Boston card?
  • Anyone know how much a rental vehicle costs at rental places contained by southern CA, and what is required?
  • Cash or travellers cheque or maestro card surrounded by USA?