c. 1920 — Dr. William "Doc" Reynolds, a dentist, founded Colorado's first experimental radio station, 9ZAF, at his 1124 S. University home in Denver. The studio was on the front porch and the transmitter was in the back yard. On March 10, 1922, the station's call sign changed to KLZ, then-Secretary of Commerce Herbert Hoover granted Reynolds one of the first commercial broadcasting licenses in the country, and KLZ became Colorado's first commercial radio station.
1947 — KLZ-FM, broadcasting on 106.7 MHz, became the first FM station on the air west of St. Louis.
March 12, 1949 — KLZ received "the small station Alfred I. duPont Award for meritorious service" for its medical series, "Knave of Hearts."
Nov. 1, 1953 — KLZ-TV (channel 7) went on the air as a CBS affiliate.
1954 — KLZ debuted Denver's first call-in shows.
1956 — KLZ-FM goes rock.
1957 — KLZ-TV won a Peabody Award for Panorama, a weekly public affairs series.
1949 — Aladdin Radio and Television, Inc. bought KLZ.
1954 — Time–Life Broadcasting Co., Inc. bought KLZ Radio & TV from Gaylord.
1972 — Time–Life sold KLZ-TV to McGraw-Hill, and the station's call sign changed to KMGH-TV.
Feb. 12, 1972 — Time–Life sold KLZ-AM and KLZ-FM to Group One Broadcasting Co., West for $2,750,000. (Group One was 45% owned by Knight Newspapers, and 55% owned by Roger G. Berk, Sr. and associates.)
May 1977 — According to radio historian Tom Mulvey, KLZ was sold to the Roger Berk family at this time. This probably means that Group One Broadcasting became 100% owned by the family (i.e., Knight Newspapers' 45% share was bought out).
1987 — Group One sells KLZ/KAZY to DKM Broadcasting.