I recently learned that a boundary between two Canadian provinces, Saskatchewan and Manitoba, passes through the town of Flin Flon.
At first I thought that could not happen in the U.S.A. because there is no federal authority to incorporate municipalities; that belongs only to the states.
(There are cases like Kansas City – I think several such cases – where two adjacent municipalities with the same name are separated by a state line. I seem to recall also hearing of such a situation involving the boundary between Virginia and Tennessee.)
Then it occurred to me that there may be complications:
In incorporated territories of the United States (among which today there is only Palmyra Island, and maybe D.C. if that is a "territory") there is federal authority to incorporate municipalities. I would guess that comes from the "necessary-and-proper" clause in the Constitution.
Could an interstate compact create such a situation? (I'm not sure why that would be done, but maybe it could make a local government more efficient and in particular less costly.)
So I wonder: (1) To what extent, if at all, might this be possible in the U.S., and (2) are there other such cases in Canada, and if so, why? (In Flin Flon, it does seem that efficiency of local government might be the reason.)