yep, used globally depending on the time of day. the other freq. is 11.253 Mhz. A more reliable propagation beacon would be the 2.5,5,10, 15 and 20 MHz international clock you can make out. Series of pips... Long tone starts on the minute.
http://en.wikipedia.org/wiki/WWV_%28radio_station%29
All hopefully to be replaced by more modern weather gathering methods over the next few years... Nothing worse than HF when there are better and cheaper alternatives!