Mystery Hunt 1994 / Puzzle 10 Solution

This one was short and sweet... an example of how open-ended the puzzles sometimes are. That doesn't mean it was actually quick to solve, however.

The numbers are telephone area codes.

The states can also be represented by their two-letter postal codes.

Substituting the postal codes for the area codes gives:

414 + 701 = 717 + 402
WI  + ND  = PA  + NE
so WIND and PANE are a solution pair.