The Denver-Boulder area is one of the top thirty biggest radio markets in the country. The history traces back to the earliest days of commercial radio in the early 1920s. The earliest licensed call letters at that time included KDYY, KDZQ, KFAF, KLZ, KOA and the University of Colorado's KFAJ. By the early forties the AM dial included KLZ (560), KVOD (630), KOA (850), KPOF (910), KFEL (950) and KMYR (1340).

AM radio, driven by national networks, was overshadowed by the popularization of television in the fifties. But radio reinvented itself first with the advent of mass appeal stations aimed at specific demographics, then with the popularization of transistor radios, and then in the sixties with increasing audiences of FM stations.

During the late sixties experimental formats were brewing around the country on the FM dial. In Denver freeform started with KFML (98.6), which was the simulcast of its sister 1390 AM in the spring of 1968. KMYR briefly played with freeform the following year, then KRNW (97.3) out of Boulder went freeform in January 1970. Later in the decade the station became KBCO. KFML became country station KIMN in 1974 after it was acquired by Jefferson-Pilot. The call letters later changed to KYGO.

FM inevitably became the band for music listeners by the early eighties. By the end of the eighties the number one station in Denver, according to Arbitron, was album rocker KBCO (1190 AM and 97.3 FM). At the time KBCO was owned by Noble Broadcasting. At times competition was tight with Summit's KAZY (106.7) and Sandusky's KBPI (105.9). Other top stations by the end of the eighties were Shamrock's oldies outlet KXKL (1280 AM and 105.1 FM), Cap Cities/ABC's contemporary hits leader KRXY (1600 AM and 107.5 FM), Jefferson-Pilot's country leader KYGO (98.5), Anderson's top 40 challenger KQKS (104.3) and D&D's beautiful music music station KOSI (101.1). The strongest performing AM station was talk-formatted KOA (850), owned by Jacor.

In the nineties KOA-AM emerged at the top station in the area, continuing to be driven by talk. KYGO, KOSI and KQKS also continued to be leading stations. Following the Telecom Act of 1996, which loosened ownership limit rules, the first three big players in the market were Jacor, Jefferson-Pilot and Chancellor Media. Jacor owned KOA, classic rocker KRFX, adult alternative KBCO, rocker KBPI and AM talk stations KHOW 630 and KTLK 760.

Jefferson-Pilot owned KYGO AM & FM, KQKS, country station KCKK 104.3, which had swapped frequencies with KQKS and sports/talk station KKFN (950 AM). Chancellor owned adult contemporary hits station KALC (105.9), oldies then adult contemporary sister KIMN (100.3) and classical station KVOD (92.5), oldies station KXKL (105.1) and adult alternative challenger KXPK (96.5 FM "The Peak"). At the end of the decade Chancellor became AMFM and then merged with Clear Channel.

In the 2000s KBCO has continued to be among the top stations in the market along with KYGO, KQKS, KOA-AM and KOSI. At the midway point of the decade Clear Channel owns eight stations in the market: KOA-AM, KRFX, KBPI, KTCL, KHOW-AM, KMGG and KKZN-AM. Jefferson-Pilot owns KYGO, KQKS and KJCD (Smooth Jazz). Another big company, Entercom, owns KOSI, KQMT, KALC and KEZW-AM.