North west central? Should that be interpreted as Minnesota, the Dakotas, Iowa, Missouri, Kansas and Nebraska? (that's what I would guess from what you say, just to make things clear)
These are the US census bureau regions btw, I didn't make this garbage up. 
They are
Census Divisions. There are 4
Census Regions, Northeast, Midwest (North Central before 1984), South and West. The regions and divisions are mainly used for data presentation. This is particularly useful for diagrams such as interstate migration where a 51 by 51 grid of migration counts is hard to understand if the states are alphabetized, but if gathered by division and region. States can also be geographically ordered within divisions, which harkens back to the traditional north to south ordering of the states (the Constitution is signed in geographical order).
Sometimes the regions can be somewhat misleading. The two most populous states in the South region, Texas and Florida are somewhat atypical of the rest of the region. Similarly, California has such a large share of the West region's population that it dominates its statistics.
The North Central region was renamed to the Midwest after congressmen and politicions from the region complained that no one knew where "North Central" was. Nonetheless it was retained in the names of the constituent divisions which are BTW
East North Central and West North Central, not North East Central and North West Central The same distinction is made for the 2 westernmost divisions of the South Region.
