KPLY is a Sports radio station that went on the air as KOH, it was the last "new station" in the United States to receive a three-letter callsign but only retained it for less than a year.
The station went on the air as KOH on 1928-09-13, and is the oldest radio station in Nevada. KOH retained this call until 1994-03-10 (1994-03-18, by FCC records). 
