One hundred years ago today, on March 10, 1922, Dentist William “Doc” Reynolds was granted the 67th commercial radio license nation-wide and the first in Colorado. The station was assigned the call letters KLZ, recycled from the SS Speedwell, a ship that had sunk in the Gulf of Mexico two years earlier.

Doc’s original license allowed him to broadcast only on Sunday, Tuesday and Friday from 8 to 9:30pm at 833 Kilocycles. There were only two frequencies at the time, that any stations would share 360 meters/833 Kilocycles (what we’d think of now as 833AM) for “entertainment” broadcasts, and 485 meters/619 Kilocycles (or 619AM) for “market and weather” reports. He broadcast from his house, where he’d been broadcasting experimental station 9ZAF s ince 1919.

On March 10, 1922, KLZ was Colorado’s first and only licensed commercial station. Over the next days and weeks, more stations would be licensed in Denver and across the state and country.

A dentist in Colorado Springs,”Doc Reynolds” established wireless parts wholesaler “The Reynolds Radio Company” in 1914 (incorporated in 1921). In 1918, he was “on the air” in Colorado Springs with an amateur radio station named 9WH.

In 1919, he moved to Denver and started amateur station 9ZAF at his home at 1124 S. University Avenue. In December 1921, the Navigation Bureau of the Department of Commerce issued rules that included the need to be licensed.

On March 10, 1922, Variety Magazine reported that there were a million radios nation-wide. Commercial radio was just beginning, and that same day a hundred years ago, Colorado would get its first licensed commercial radio station. Experimental station 9ZAF became KLZ one hundred years ago, and commercial radio in Colorado began.