I have often wondered what the time line looks like for the different transitions of phone #'s in NV. Specifically when some cities or regions moved from the 4 or less digit extension to the alpha-numeric system to the 7 digit #'s and then to the 7 digit w/ area codes common today. To make these determinations for Las Vegas only would be helpful in organizing my match covers but just to know these facts is interesting to me. Eric