1991 Sierra Madre earthquake

KJLA (channel 57) is a television station licensed to Ventura, California, United States, serving the Los Angeles area as an affiliate of Visión Latina. The station is owned by Costa de Oro Media, LLC, a company run by Entravision Communications founder, CEO and chairman Walter Ulloa (whose brother, Ronald Ulloa, owns Rancho Palos Verdes–licensed ethnic independent station KXLA (channel 44) and Twentynine Palms–licensed KVMD (channel 31)). KJLA's studios are located on Corinth Avenue (near Interstate 405) in West Los Angeles, and its transmitter is located atop Mount Wilson. KJLA operates two low-power repeater stations: KLFA-LD (channel 25) in Santa Maria and KFUL-LD (channel 23) in San Luis Obispo (both are part of the Santa Barbara market). In addition to carrying Spanish-language programming on its main channel, the station also carries various networks broadcasting in Vietnamese and Mandarin on separate digital subchannels.

KXLA (channel 44) is an ethnic independent television station licensed to Rancho Palos Verdes, California, United States, serving the Los Angeles area. The station is owned by Rancho Palos Verdes Broadcasters, Inc., whose president and majority owner, Ronald Ulloa, also owns Twentynine Palms–licensed KVMD (channel 31). KXLA's studios are located on Corinth Avenue (near Interstate 405) in West Los Angeles, and its transmitter is located atop Mount Wilson.

KFTR-DT (channel 46) is a television station licensed to Ontario, California, United States, serving the Los Angeles area as the western flagship station of the Spanish-language UniMás network. It is owned and operated by TelevisaUnivision alongside Univision station KMEX-DT (channel 34). Both stations share studios on Center Drive (near I-405) in Westchester, while KFTR-DT's transmitter is located atop Mount Wilson. KFTR does not air any local newscasts of its own; however, the station does cross-promote sister station KMEX's local news programs.

KPWR (105.9 FM) – branded as Power 106 – is a commercial radio station in Los Angeles, California, broadcasting to the Greater Los Angeles area. KPWR is owned and operated by Alex Meruelo's Meruelo Group, through licensee KPWR Radio Holdings LLC, and airs a Rhythmic Hot AC format. KPWR's studios are based in the Los Angeles suburb of Burbank, and the transmitter is on Mount Wilson, shared with KCAL-TV and KRTH. Meruelo acquired KPWR from Emmis Communications for $82.75 million in May 2017, officially bringing the station under common ownership with KDAY, KDEY-FM, KWHY-TV, and KBEH on August 1, 2017.

KNBC (channel 4) is a television station in Los Angeles, California, United States, serving as the West Coast flagship of the NBC network. It is owned and operated by the network's NBC Owned Television Stations division alongside Corona-licensed Telemundo outlet KVEA (channel 52). Both stations share studios at the Brokaw News Center in the northwest corner of the Universal Studios Hollywood lot off of Lankershim Boulevard in Universal City, while KNBC's transmitter is located on Mount Wilson.

KTTV (channel 11) is a television station in Los Angeles, California, United States, serving as the West Coast flagship of the Fox network. It is owned and operated by the network's Fox Television Stations division alongside MyNetworkTV outlet KCOP-TV (channel 13). Both stations share studios at the Fox Television Center in West Los Angeles, while KTTV's transmitter is located atop Mount Wilson.

KCOP-TV (channel 13) is a television station in Los Angeles, California, United States, serving as the West Coast flagship of MyNetworkTV. It is owned and operated by Fox Television Stations alongside Fox outlet KTTV (channel 11). Both stations share studios at the Fox Television Center located in West Los Angeles, while KCOP-TV's transmitter is located atop Mount Wilson.

The Infrared Spatial Interferometer (ISI) is an astronomical interferometer array of three 1.65 m (5 ft 5 in) telescopes operating in the mid-infrared. The telescopes are fully mobile and their current site on Mount Wilson allows for placements as far as 70 m (230 ft) apart, giving the resolution of a telescope of that diameter. The signals are converted to radio frequencies through heterodyne circuits and then combined electronically using techniques copied from radio astronomy. ISI is run by the University of California, Berkeley Space Sciences Laboratory. The longest (70 m (230 ft)) baseline provides a resolution of 0.003 arcsecond at a wavelength of 11 micrometres. On 9 July 2003, ISI recorded the first closure phase aperture synthesis measurements in the mid infrared.

KTLA (channel 5) is a television station in Los Angeles, California, United States, serving as the West Coast flagship of The CW Television Network. It is the largest directly owned property of the network's majority owner, Nexstar Media Group, and is the second-largest operated property after WPIX in New York City. KTLA's studios are located at the Sunset Bronson Studios on Sunset Boulevard in Hollywood, and its transmitter is located atop Mount Wilson. KTLA was the first commercially licensed television station in the western United States, having begun operations in January 1947. Although not as widespread in national carriage as its Chicago sister station WGN-TV, KTLA is available as a superstation via DirecTV and Dish Network (the latter service available only to grandfathered subscribers that had purchased its a la carte superstation tier before Dish halted sales of the package to new subscribers in September 2013), as well as on cable providers in select cities within the southwestern United States and throughout Canada. As of 2015, KTLA operates an internet-only news radio channel on iHeartRadio.

KLLI (93.9 MHz, "Cali 93.9") is an FM radio station in Los Angeles, California. Owned by the Meruelo Group, it broadcasts a bilingual Latin pop/rhythmic contemporary format. The station has studios located in Burbank, while its transmitter is based on Mount Wilson, and broadcasts in the HD Radio format.

KABC-TV (channel 7) is a television station in Los Angeles, California, United States, serving as the West Coast flagship of the ABC network. Owned and operated by the network's ABC Owned Television Stations division, the station maintains studios in the Grand Central Business Centre of Glendale, and its transmitter is located on Mount Wilson.

KRCA (channel 62) is a television station licensed to Riverside, California, United States, broadcasting the Spanish-language Estrella TV network to the Los Angeles area. It is the flagship television property of Burbank-based Estrella Media. The station's studios are located on North Victory Drive (near Interstate 5) in Burbank. Through a channel sharing agreement with KABC-TV (channel 7), KRCA transmits using KABC-TV's spectrum from an antenna atop Mount Wilson. Despite Riverside being KRCA's city of license, the station maintains no physical presence there.