Yes, these are Marijuana-themed radio stations. This week in Denver, CO 94.1 "Mile High Sports Radio" KCKK flipped to KBUD, also known as "Smokin' 94.1" In March, the station and its AM signal at 1550 AM were sold to Marco Broadcasting who changed up the formats. The state of Colorado infamously legalized marijuana for recreational purposes in 2012 to much political melodrama. The end result appears to have been a drop in crime, increased tax revenues and a somewhat silly radio format. But this was not the first Marijuana-themed radio station in Colorado.
Just back in April, 1580 KREL-AM a former ESPN and Fox Sports Radio affiliate changed calls to KHIG and flipped formats to K-HIGH, a marijuana-talk station. But the Colorado Springs area station was just stunting. In May they flipped again to a simulcast of soft AC-formatted 101.3 KFEZ as "Easy 101.3." More here. They were preceded in 2012 by "Pot 107.1" a stunt by Max Media property KDHT in Denver. The first song on their playlist was "Rocky Mountain High" by John Denver. The stunt lasted all of 24 hours when they debuted a Jack-branded Adult Hits format.
Just last year Siriux XM radio and High Times magazine co-launched a music channel called "Reefer Radio." The channel had a limited run and wrapped up in July after running the prerequisite Tommy Chong and Snoop Dogg interviews. However, it wasn't SiriusXM nor any Coloradan broadcaster that invented this radio format. It's origin is a bit hazy as it so happens. In 1971 Vice President Agnew railed against "dope lyrics" on the radio. On March 5th the FCC issued a public notice effectively banning pro-drug lyrics from radio. The statement read "...we expect broadcast licensees to ascertain, before broadcast, the words or lyrics of recorded musical or spoken selections played on their stations." they backed it up with the threat of a $5,000 fine. This wasn't hyperbole. The FCC had already banned cigarette and liquor advertising. The commission later stated that they'd welcome a test case. There were numerous first amendment concerns, but the major networks, and NAB obeyed for the most part. More here and here. But some types of stations ignored the rules.
1985-1994 - KNBS - "Cannabis Shortwave" (Wellsville, NY)Author Andrew Yoder listed off those and a few others in his books Pirate Radio Stations and Pirate Radio. So drug music (if I can call it that) didn't go away, it moved to Free Form FM radio, shortwave and pirate radio. I can think of several pirate radio stations that were Marijuana-themed dating back decades, many on shortwave. It's axiomatic that they begin to appear shortly after end of Free Form FM radio. then they fade away as the social norms change and the rule fades away.
1991-1997 - KMCR - "Magic Carpet Radio" (California)
1992-1993 - WEED Shortwave (Arizona)
1992-2004 - Radio Free Euphoria [LINK]
1994-1995 - 6YVOS - "Voice of Smoke" (Wellsville, NY) [LINK]
2004-2013 - WEED-FM (Merseyside, England)