|Broadcast area||Denver metro area|
|Branding||103.5 The Fox|
|Slogan||Colorado's Classic Rock|
|Frequency||103.5 MHz (also on HD Radio)|
|Translator(s)||107.9 K300CP (Denver, relays HD2)|
|First air date||June 1, 1961 (as KOA-FM)|
|Format||Classic rock (Analog/HD1)
Sports (KDSP simulcast) (HD2)
|Callsign meaning||KoloRado FoX|
|Former callsigns||KOA-FM (1960–1974)
(Citicasters Licenses, Inc.)
|Sister stations||KBCO, KBPI, KDSP, KHOW, KPTT, KOA, KTCL|
KRFX (103.5 FM) – branded 103.5 The Fox – is a commercial classic rock radio station licensed to Denver, Colorado serving the Denver metro area. The KRFX studios are located in Denver, while the station transmitter resides in Golden, and it is owned by iHeartMedia, Inc..
The station signed on the air on June 1, 1961 as KOA-FM; the station first broadcast middle of the road (MOR) and later a beautiful music format. The radio station was co-owned with KOA-TV (Channel 4). Studios were located at 1044 Lincoln Street. In 1968 KOA Radio and TV were purchased by General Electric Broadcasting. By 1974, KOA-FM would flip to Top 40 as KOAQ "Q103," where it would enjoy a successful run and become one of Denver's top-rated stations during the early 1980s. Jack Regan was the station's long-time program director and morning DJ. Alan Sledge was music director, and held down the mid-day shift. He later added assistant PD duties. In late 1983, General Electric sold KOA and KOAQ to Belo Corporation of Dallas for $22 million. Lee Larson was selected as the new General Manager. He came to Denver from KLOS in Los Angeles. In 1987, Jacor Communications purchased KOA/KOAQ for $24 million. After nearly 14 years playing Top 40, on January 18, 1989, they would flip formats to classic rock and adopt the KRFX call letters, becoming "103.5 The Fox", one of several stations in the U.S. using the brand "The Fox".
KRFX personalities include: Rick Lewis mornings; Colfax middays; and Roger King evenings. On Sunday evenings, the station carries the regionally syndicated Strictly Blues with host Kai Turner. The station also holds the local FM rights for the play-by-play for the Denver Broncos, sharing the games with sister station KOA (850).