 Its studios are located in Denver near Sports Authority Field at Mile High, and the transmitter is west of Castle Rock.KJMN signed on the air in 1979 as adult contemporary KMJD, but would go through various formats and call letters as rock outlets KRKY (1983–84), KADX (1984–88) and KZRZ (1988–89), country and talk KYBG (1989–95), and modern rock KNRX (1995–96).During the KNRX stretch, 92.1 was called "92-X," and catered to the modern rock and alternative rock listeners.