KMBR was born on December 13, 1996, when it switched over from its old call letters (KQUY) and branding (Y-95). Y-95 played a Hot AC format featuring artists like Mariah Carey, Madonna, Huey Lewis and Richard Marx. KMBR shifted the emphasis to "Montana's Best Rock", featuring core artists such as Led Zeppelin, Van Halen, AC/DC, Lynyrd Skynyrd and more. The original mainstays were Uncle Dave Levin in the mornings, the ArchMan with the "Power Lunch" from 10a - 3p, and Robin Taylor (later Robin Jordan) with afternoons. Currently KMBR features "The Brian and Chris Show" in the Mornings, Middays with Carin Sullivan, Your Show with Jasmine during PM drive, syndicated evenings On Tap with Nick Carter, followed by jock-free rock in the overnights.
The station carries the weekly syndicated Pink Floyd program Floydian Slip as well as Rockline, Flashback and Breakfast with the Beatles.
KMBR and its sister stations are all located at 750 Dewey Blvd. in Butte. The rear of this radio facility houses the small studios of the local NBC affiliate, KTVM Channel 6. KAAR and KMBR share a transmitter site northeast of town, east of Interstate 15.