Alt-rock radio mainstay KFOG 104.5 is signing off after 36 years on the air.

On Monday, the San Francisco station announced it would flip to a simulcast of KNBR-AM sports radio on Sept. 6, leaving longtime "Fogheads" with just over a week to savor the sounds of artists like Jefferson Airplane, Green Day, the Red Hot Chili Peppers and Smashing Pumpkins.

A statement released by Cumulus Media explained that the expansion of KNBR would offer sports fans another place to tune into "high-profile personalities and in-depth coverage of the Bay Area's favorite teams," plus a stronger signal and broadcast range.

"It's never easy to say goodbye to a station, and we want to thank the staff, listeners, and advertisers who together made KFOG the legendary and beloved station that so many of us in San Francisco had the opportunity to enjoy," said Doug Harvill, vice president and marketing manager of Cumulus San Francisco.

He added that Cumulus is excited to bring KNBR to a wider audience.

KFOG's morning radio fixture, "The Woody Show" took to Twitter to share their feelings on the news.

"We knew this was gonna happen the minute the company who owns KFOG sold the 97.7 San Jose frequency," they wrote. Their stint on KFOG was actually their second, originally airing in San Francisco on "Live 105" 105.3 KITS in 2006.

"It's an impossible task when nobody can hear the radio station. Without San Jose and east bay, you can't compete. That said, we love ya! Listen to the podcast!"

Fans and listeners were devastated.

"Not even a proper burial for KFOG?" one Twitter user responded to KNBR program director Jeremiah Crowe when he shared his excitement for the station's growth. But it's somewhat standard for the radio industry, which is traditionally unceremonious when dropping DJs and programming.

KFOG was one of the few surviving links to San Francisco's rich history of free-form radio on the commercial dial. At its peak, it was once ranked seventh out of up to 40 radio stations owned by Cumulus Media. The station began as KBAY-FM in 1960, operated under Kaiser Broadcasting as an instrumental feel-good listening station.

The call sign switched to KFOG four years later and it became a rock station in 1982, famously snubbing mass-appeal bands in favor of psychedelic tunes and emerging artists.

It was a people-powered station that rewarded its fans with tickets to private in-studio concerts, compiling the intimate sets for 22 years on an annual CD called "Live from the Archives." The proceeds were donated to local food banks.

KFOG also put on an annual concert and fireworks show – the KFOG KaBoom – for nearly 16 years, drawing upwards of 350,000 people to the San Francisco waterfront. It attracted artists like Melissa Etheridge, Collective Soul and Train.

In 2018, Rosalie Howarth – the last of the longtime KFOG DJs – announced she would be leaving her show "Acoustic Sunrise" after 34 years. She had been involved in the Bay Area music scene since she ran away to Haight-Ashbury for the Summer of Love.

Her final words on the air: "You guys have been the best, and we were the luckiest ones."

Amanda Bartlett is an SFGate editorial assistant. Email: amanda.bartlett@sfchronicle.com