Broadcast areaSan Francisco Bay Area
Frequency107.7 MHz (HD Radio)
Branding107.7 The Bone
FormatMainstream rock
AffiliationsSan Francisco 49ers Radio Network
First air date
April 1, 1963 (1963-04-01) (as KUFY)
Former call signs
KUFY (1963–1968)
KVEZ (1969–1974)
KSOL (1974–1994)
KYLD (1994–1997)
Call sign meaning
San Mateo
Technical information
Facility ID14484
ERP8,900 watts
HAAT354 meters (1,161 ft)
Transmitter coordinates
37°41′20″N 122°26′11″W / 37.68889°N 122.43639°W / 37.68889; -122.43639
Repeater(s)See § Booster
WebcastListen Live
Listen via Audacy

KSAN (107.7 MHz, "107.7 The Bone") is a commercial FM radio station licensed to San Mateo, California, and serving the San Francisco Bay Area. It is owned and operated by Cumulus Media and it airs a mainstream rock radio format. It also serves as the FM flagship station for the San Francisco 49ers Radio Network. KSAN's studios and offices are located on Battery Street in San Francisco's SoMa district.[1]

KSAN has an effective radiated power (ERP) of 8,900 watts. Its transmitter is off Radio Road on San Bruno Mountain in Brisbane, California.[2] KSAN broadcasts in the HD Radio hybrid format.



On April 1, 1963, KUFY signed on the air. It was the FM counterpart of KOFY (now KTCT), owned by Intercontinental Radio, Inc. While the AM station aired a Regional Mexican format, KUFY played beautiful music, mostly instrumental cover versions of popular songs along with Hollywood and Broadway showtunes.

Because KUFY played easy listening music, the call sign changed to KVEZ in 1968.


In 1975, the station flipped to an urban contemporary format and took the call letters KSOL for "K-Soul".[3] The original K-Soul broadcast on 1450 AM (now KEST). KSOL became the first urban radio station on the FM dial in the San Francisco Bay Area. Local musician Sly Stone played a part in influencing the station to make the switch.

While KSOL managed to fend off competition from KBLX unscathed throughout the 1980s, KSOL's ratings began to decline due to competition from KMEL, then a Top 40 station which was slowly evolving in a rhythmic contemporary format before going in a mainstream urban direction. Eventually, the decision was made to end KSOL and its format. The DJs were notified beforehand and held a goodbye show to send off KSOL on February 10, 1992. The final song on KSOL was "Miss You Much" by Janet Jackson. Afterwards, KSOL segued into a 72-hour loop of "Wild Thing" by Tone Lōc.


On February 13, 1992, 107.7 FM flipped to rhythmic contemporary, branded as "WiLD 107". The first song on "WiLD" was "D.M.S.R" by Prince.[4] For the first year and a half, the station retained the old KSOL call letters.

Allen Shaw's Crescent Communications bought the station in December 1993 for $13.5 million.[5] KSOL's call letters were changed to KYLD the following year. The company also purchased 99.1 in San Jose from Viacom, and began simulcasting KYLD's programming in the South Bay, to expand coverage. Program Director Rick Thomas and Music Director Michael Martin set a plan in motion to overtake KMEL; they came up with a strategy of playing "old school" and up tempo freestyle/dance songs like those heard on heritage San Jose radio station HOT 97.7. KMEL moved from rhythmic to urban contemporary at the same time, and the two stations battled with each other throughout the mid-1990s.


At 12:01 a.m. on July 2, 1997, KYLD moved to 94.9 FM. 107.7 and 94.9 would simulcast until Midnight on July 7, when 107.7 FM, now with the KSAN call letters, began stunting with construction noises and song clips as a prelude to a flip to classic rock at noon on July 11.[6]

On March 13, 2000, after playing "Goodbye Yellow Brick Road" by Elton John, followed by a stunt with funeral bells, the station relaunched as "The Bone", playing classic rock with a harder edge. To initiate this change, the station played AC/DC "A to Z", all 154 songs the band had recorded at that point, aired in alphabetical order.[7]

Classic to mainstream rock

With the demise of rival rock station KSJO in 2004, the station adopted a mainstream rock format. The playlist shifted back toward classic rock in April 2017. The current playlist consists of hard rock staples from the '60s to mid 2000s.[8] The weekday on-air staff at The Bone consisted of morning team Lamont & Tonelli, as well as Chasta, Steven Seaweed and Zakk.

In early 2016, Steven Seaweed's "All Request Hot Lunch" was cancelled by the program director. In August, Lejf Jaeger left the Bone. He had been part-time weekends for ten years. With his departure, "Local Licks" was also removed from the programming.[citation needed]

Steven Seaweed retired on July 1, 2017, after 44 years of deejaying in the Bay Area, the last 20 of which had been with KSAN.[9]


Throughout the NFL season, the station broadcasts San Francisco 49ers games. While co-owned KNBR and KTCT are the primary flagship stations for the team, KSAN also airs the games.


KSAN (FM) is rebroadcast on the following FM booster:

Call sign Frequency City of license FID ERP (W) HAAT Class FCC info
KSAN-FM1 107.7 FM Pleasanton, California 28878 185 (Horiz.) 926 m (3,038 ft) D LMS

HD Radio

KSAN broadcasts in the HD Radio format with the following stations:

From 2016 to 2018, the HD2 channel carried the Nash FM country music network.[10]


  1. ^ "Station Information". KSAN-FM.
  2. ^ "KSAN-FM 107.7 MHz - San Mateo, CA". radio-locator.com.
  3. ^ Broadcasting Yearbook 1976 page C-26
  4. ^ "KSOL Becomes Wild 107.7" from FormatChange.com
  5. ^ Broadcasting & Cable Yearbook 1994 page B-51
  6. ^ http://www.americanradiohistory.com/Archive-RandR/1990s/1997/RR-1997-07-11.pdf [bare URL PDF]
  7. ^ http://www.americanradiohistory.com/Archive-RandR/2000s/2000/RR-2000-03-17.pdf [bare URL PDF]
  8. ^ "107.7 The Bone On Air Playlist". 107.7 The Bone.
  9. ^ "Steven Seaweed Announced His Retirement From Radio!". 10 May 2017. Retrieved 28 March 2018.
  10. ^ "Nash FM No Longer On KSJO/San Francisco" from All Access (March 1, 2016)