| Sutro Tower | |
|---|---|
 Sutro Tower viewed from Grandview Park in San Francisco | |
  | |
| General information | |
| Status | Completed |
| Type | Radio mast |
| Location | San Francisco, California |
| Address | 1 La Avanzada Street Clarendon Heights |
| Coordinates | 37°45′19″N122°27′10″W / 37.75523°N 122.45284°W /37.75523; -122.45284 |
| Elevation | 254.2 m (834 ft) |
| Construction started | 1971 |
| Completed | July 4, 1973 |
| Owner | Sutro Tower, Inc. |
| Height | |
| Antenna spire | 297.8 m (977 ft)[1] |
| Observatory | on Level 6, 228.8 m (751 ft) above base |
| Dimensions | |
| Other dimensions |
|
| Technical details | |
| Structural system | Truss tower |
| Design and construction | |
| Architect(s) | Furman L. Anderson Jr.[2] |
| Architecture firm |
|
| Renovating team | |
| Engineer | Simpson Gumpertz & Heger |
| Website | |
| sutrotower | |
| References | |
| [3][4][5] | |
Sutro Tower is a unique three-legged 297.8 m (977 ft) tall TV and radiolattice tower located on theWest Side of San Francisco, California. Rising from a hill betweenTwin Peaks andMount Sutro nearClarendon Heights, it is a prominent feature of the city skyline and a landmark for city residents and visitors. The tower was the tallest structure in San Francisco from the time of its completion in 1973 until it was surpassed by theSalesforce Tower in 2018.[6]
The tower is named after Mount Sutro.[7] Adolph Gilbert Sutro, grandson of former mayorAdolph Sutro, built a mansion,La Avanzada, on the family property in the highest peaks of San Francisco. In 1948, the mansion and property were sold to theAmerican Broadcasting Company, where it became the original home of their San Francisco operation asKGO Television. KGO then formed a consortium withKTVU,KRON, andKPIX, the three other major San Francisco television broadcasters at the time, to build and maintain the tower. It stands 297.8 m (977 ft) above ground and 552 m (1,811 ft) above sea level. It is the second tallest structure in the city by ground-to-tip height, though its mountain location overlooks the city's downtown skyscrapers.
Before the construction of Sutro Tower in 1973, television reception in San Francisco was spotty because the many hills of the city blocked the line-of-sight television signal. The great height of the new tower helped to resolve that problem. Transmitters had been scattered throughout the Bay Area, including atSan Bruno Mountain,Mt. Allison,Monument Peak, andMt. Diablo. By having all the main Bay Area television station transmitters in one location, reception was improved by allowing a receiving antenna pointed in a single direction to receive all those stations rather than a subset.
Local residents opposed the tower even before it was completed, including criticism of the aesthetic effect the tower would have on the rest of San Francisco. San Francisco writerHerb Caen once wrote, "I keep waiting for it to stalk down the hill and attack the Golden Gate Bridge."[8]
When first built, the long legs of the tower were illuminated at night with long tubes of white light that looked like long fluorescent tubes. However, public outcry resulted in the lights being removed soon after they were turned on.[citation needed] Despite the initial revulsion of some residents, Sutro Tower is now recognized by many as a Bay Area icon.[9] A local entertainment guide,SF Station, uses it as a logo, as does the collaborativeart gameSFZero. In 2022, Sutro Tower was included in the video gameHorizon Forbidden West as one of the prominent landmarks in the San Francisco area.[10]
Beginning in 2019, one of the three upper antenna assemblies was temporarily removed for the installation of new antennas for theFCCspectrum repacking.[11][12][13] Antenna installation for the repacking was completed on May 1, 2020. Additionally, "To accommodate some final project cleanup work, some stations will broadcast from their auxiliary antennas intermittently between mid-July and mid-August."[14]
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Construction began in 1971 byKline Towers ofColumbia, South Carolina. The tower was completed in 1973, with the first transmissions on July 4, 1973. Approximately 3,750 m3 (132,000 cu ft) of concrete were used to make the foundation of the 1,700 ton (3.7 million pound) tower. Earthquake proofing includes ballasting two-thirds of the weight of the structure below ground, resulting in a center of gravity at sixteen feet below ground level. It is used to transmit the signals of eleven television stations and fourFM radio stations and for various other communications services.
The tower is owned by Sutro Tower Inc., anonprofit corporation, which in turn is owned by aconsortium of the four major television broadcasters in San Francisco at the time of its construction:KTVU (previously owned byCox Media Group, now owned byFox Television Stations);KRON-TV (owned by theSan Francisco Chronicle at the time of the tower's completion, now owned byNexstar Media Group);KPIX (a formerWestinghouse Broadcasting property, now owned byCBS); andKGO-TV (anABC-owned station). Sutro Tower also leases space to other Bay Area radio and television stations, includingPBS outletKQED;independent stationKOFY-TV; non-commercial stationKPJK; andKPYX, a sister station to KPIX. With the advent of channel-sharing agreements after the 2016 FCCspectrum auction,San Jose'sKQEH began to transmit from Sutro with sister stationKQED on January 17, 2018, moving from its formerMonument Peak transmitter.
Three other major Bay Area TV stations are unable to be located at Sutro Tower—theNBC-ownedduopoly ofKNTV andKSTS; and KTVU's duopoly partnerKICU-TV. KNTV, which assumed the area's NBC affiliation from KRON-TV in 2002, relocated its transmitter fromLoma Prieta Peak to San Bruno Mountain, five miles (8 km) south of Sutro Tower; KSTS and KICU-TV transmit from east ofFremont. Those locations allow these stations to maintain primary coverage overSan Jose and the South Bay, as San Jose is thecity of license for all three stations.
The facility is accessible only by authorized vehicles. The area near the site offers panoramic viewpoints of San Francisco. There is a platform near the top of the tower, 232 m (761 ft) above ground and 486.2 m (1,595 ft) above sea level.[15] Only authorized maintenance workers can access the tower via a small two-person elevator that runs inside the west tower enclosed leg. There is no public access within the Sutro Tower property lines.
On a clear day, the tower can be seen from theEast Bay peak ofMount Diablo and is sometimes the only part of San Francisco seen above the coastalfog when it is blown inland, typically on summer mornings and evenings.
TV stations that transmit from Sutro Tower include the following. Most of these stations carry additionalsubchannels on their frequencies. Subchannel affiliations are shown via the digital channels link.[16][17]
| Callsign | Virtual channel | Physical channel | Affiliation | Digital channels | Online? |
|---|---|---|---|---|---|
| KTVU | 2 | 26 | Fox | 2.1–2.4 | ✔︎ |
| KURK-LD | 3 26 | 3 | REL | 3.1-3.10 26.2 | ✘ |
| KRON-TV | 4 | 7 | The CW | 4.1–4.5 | ✔︎ |
| KPIX | 5 | 29 | CBS | 5.1–5.4 | ✔︎ |
| KGO-TV | 7 | 12 | ABC | 7.1–7.3 | ✔︎ |
| KQED KQEH | 9 54 | 30 | PBS | 9.1–9.4 54.1-54.4 | ✔︎ |
| KQSL-LD | 17 26 | 4 | REL | 17.1-17.10 26.2 | ✘ |
| KRCB | 22 | 5 | PBS | 22.1-22.3 | ✔︎ |
| KCNS KTNC-TV KEMO-TV | 38 42 50 | 32 | Shop LC (KCNS) TCT (KTNC) ShopHQ (KEMO) | 38.1–38.6 42.1-42.2 50.1-50.3 | ✔︎ |
| KPYX | 44 | 28 | Independent | 44.1-44.5 | ✔︎ |
| KQTA-LD KAAP-LD KTSF KMMC-LD KDTS-LD | 15 24 26 30 52 | 14 | JTV Diya TV Ind. (KTSF) Estrella TV Daystar | 15.1-15.10 24.1, 24.4, 24.5, 24.7 26.11 30.1, 30.2 52.1, 52.2 | ✔︎ |
| KPJK | 60 | 27 | Public Ind. | 60.1–60.6 | ✔︎ |
| KFSF | 66 | 34 | UniMás | 66.1–66.5 | ✔︎ |
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FM stations that transmit from Sutro Tower includeKEXC (Formerly KREV) (92.7),KOIT (96.5),KSOL (98.9),KOSF (103.7), andKNBR-FM (104.5).[18][19]
