What year did Arkansas's area codes get divided up?

10 points to first right answer with proof.What year did Arkansas's area codes get divided up?
Area code 501 splits to 870 in Arkansas (4/1997; completed)



Area code 501 splits to 479 in northwestern Arkansas (1/2002; completed)



I remember when these happened, especially the 870 one, because I kept thinking it was toll free, and it's not.



Thanks to the increase to cell phones to why we have more area codes than before.