KLZ (560 AM) is a commercial radio station licensed to Denver, Colorado. It airs a conservative talk radio format and is owned by Crawford Broadcasting, with studios on South Parker Road in Aurora. It is the oldest radio station in the state of Colorado, and one of the oldest in the United States.

KLZ is a Class B station powered at 5,000 watts. To avoid interfering with other stations on 560 AM, it uses a directional antenna with a two-tower array. The transmitter is on Niver Creek Trail off Steele Street in Welby. The signal covers much of the population center of Colorado, from Fort Collins to Colorado Springs and Pueblo. The station is licensed to broadcast using HD Radio technology. In addition, listeners in Denver can hear KLZ programming on 99-watt FM translator K264BO at 100.7 MHz.

KLZ airs a mix of local and national conservative talk programs, branded as "KLZ Radio." Local shows are largely paid brokered programming. Topics include money and investing, real estate and health. Nationally syndicated programs include The Dana Loesch Show and The Mike Gallagher Show.

While religious radio shows are only broadcast on Sunday mornings on KLZ, Crawford Broadcasting owns two Christian talk and teaching stations in the Denver area, 810 KLVZ and 1220 KLDC. KLZ describes itself several times each hour as "God and Country" radio.

KLZ was first licensed as a broadcasting station on March 10, 1922, to the Reynolds Radio Company of Denver, Colorado. The company's president, Dr. William D. "Doc" Reynolds Jr., had earlier experimented with radio broadcasts, and the station traditionally traces its founding to 1919 or 1920.

In September 1915, Reynolds, then living in Minneapolis, was issued his first license for an amateur radio station with the call sign 9WH. This initial station employed a spark transmitter that could only transmit the dots-and-dashes of Morse code. With the entrance of the United States into World War I in April 1917, all civilian radio stations were ordered to cease operations for the duration of the conflict.

In late 1919 the amateur radio ban was ended and Reynolds, who had subsequently moved to Colorado Springs, relicensed his amateur station, which was now issued the call sign of 9JE. During the war, vacuum tube radio transmitters had been developed that made audio transmissions practical. Reynolds began work with the U.S. Forestry Service to evaluate the practicality of using radiotelephones to aid department communication. He also took advantage of the equipment provided by the Forestry service to experiment with entertainment broadcasts, and one of his first radiotelephone tests, in May 1920, provided musical selections for a dance held by students at a local high school.

In late October 1920, a newspaper account stated that Reynolds was broadcasting nightly concerts. This report also noted he had decided to suspend his dental practice to devote full-time attention to radio. He founded the Reynolds Radio Specialty Company, which was located at his home on South Prospect Street. The following February, another newspaper article stated that he had been broadcasting regular Sunday evening concerts. The article also said Reynolds was making plans to move his family and his company to Denver. (Reflecting this change, the Commerce Department's June 1921 amateur station call book entry for 9JE lists its new location as Denver, operated by the Reynolds Radio Specialty Co.)