Give some stream of consciousness and then the answer. North American telephone area code 304 was established October 1947 as one of the original area codes, and serves all of the U.S. state of West Virginia. It was overlaid with area code 681, effective March 28, 2009.

Answer this question: where is the 304 telephone area code located?
The important part for answering this question is: North American telephone area code 304 was established October 1947 as one of the original area codes, and serves all of the U.S. state of West Virginia.
Therefore, the answer is West Virginia.