The San Gabriel Mountains are the northern limit of Los Angeles, the rim of the urban bowl. Though immobile, they are in flux; moving upwards, due to the mountain building tectonics of the San Andreas fault - falling down, due to the erosional effects of winter rains, summer fires, and gravity.

When measured from the base to the top - the peak of 10,064 foot Mount San Antonio (also known as Mount Baldy) - the San Gabriels are taller than the Rocky Mountains. This vertical shift, next to the second largest city in the United States, presents both a challenge and an opportunity. At the base of the mountains lies an extensive system of flood control structures designed to hold back the cascading debris that tumbles down the disintegrating mountains. On the peaks of the mountains, antennas radiate the transmissions of the city - its television, radio, taxis, fire, police, and telephones – telecommunications that hold the social fabric of the city together. The mountains are an ally as well as a menace.

These debris basins and antenna sites show the divergent links between humans and the wild: At the top, the mountains are surmounted and used as an electromagnetic platform of social communication and control, radiating forever outward. At their base they must be contained, their inevitable collapse restrained, as they threaten our engineered landscape, and the fragile order we have established.

DISINTEGRATION

Debris basins can be found at the base of many of the vertiginous washes and canyons in the San Gabriels. The function of the debris basin is to separate debris, including rocks, mud and vegetation, from the storm water that flows down the mountains during the winter rainy season and thereby prevent damage to property and downstream flood control structures. A debris basin usually consists of an earthen dam, an excavated pit, and a spillway to channel water past the dam. Pipe spillways, as seen in the video, are vertical pipes with perforations to allow water to be separated from debris. Debris basins require constant maintenance - once they reach about 25% full the debris needs to be removed, trucked off, and disposed of. Due to encroaching development, disposal sites for the debris are getting further away, adding to their expense.

DEBRIS BASINS

Haines Canyon Debris Basin
Blanchard Debris Basin
Cooks Debris Basin
Dunsmuir Debris Basin
Lincoln Debris Basin
West Ravine Debris Basin
Fern Debris Basin
Fair Oaks Debris Basin
Rubio Debris Basin
Lannan Debris Basin
Big Dalton Debris Basin

DISSIPATION

The antenna sites depicted here form a line along the southernmost ridges and peaks of the San Gabriels. From this elevation, more than a mile above the Los Angeles basin, and with proximity to the city, these sites allow for line-of-sight communications, and for the exposure of the maximum urban area to the electromagnetic emissions of industry, entertainment, and government. The Forest Service, which owns and manages most of the San Gabriels, has set aside twenty-seven areas in the Angeles Forest for “Designated Communications Sites.” The most congested of these sites, at Mount Wilson, is one of the densest “RF jungles” in North America. Thousands of feet separate these antenna sites from the debris basins below.

ANTENNA SITES

Los Pinetos
Loop Canyon
Contract Point
Mount Lukens
Mount Disappointment
Mount Wilson
Mount Harvard
Santa Anita
Arcadia
Johnstone Peak
Sunset Ridge

A Journey to the Top of the City of Los Angeles
A CLUI walking tour

This PDF download contains a text description of a bike/hike tour in the San Gabriel mountains above Los Angeles.

This tour is a 10.6 mile round trip hike or bike ride with 2,800 feet of elevation gain on a fire road. The journey begins in Haines Canyon and concludes at an antenna farm, atop the highest point in the City of Los Angeles, 5,074 foot Mt. Lukens. Along the way you will see evidence of the interaction of the built landscape with the precipitous mountains that surround the urban fringe of Los Angeles.

  Download the tour PDF.**

  Download the Google Earth placemark file featuring the 22 antenna sites and debris basins featured in the exhibit. ***

Acknowledgements

Research + Production:
Erik Knutzen & Steve Rowell
Matthew Coolidge & Sarah Simons

Special Thanks To:
Matt Maxon, Nicholas Press, Kelly Coyne

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This exhibit is made possible in part by The Department of Cultural Affairs, City of Los Angeles
and the CLUI Electromagnetic Studies Program

*Requires Apple Quicktime
**Requires a PDF viewer such as Adobe Acrobat
***Requires Google Earth

All work on this site is licensed under a Creative Commons License.