!*OURNEYTOTHE4OPOFTHE#ITYOF,OS!NGELES Human activity in the San Gabriels includes flood off from public use, this one is open and is even !#ENTERFOR,AND5SE)NTERPRETATION7ALKING4OUR control structures, ski lifts, roads, mines, utility cor- stocked with fish. ridors, observatories, and the many electronic sites that broadcast radio and television signals to the me- Check Dams This tour is a 10.6 mile round trip hike or bike ride with 2,800 tropolis below. Between 1922 and 1927, physicist N 34º 15.44' W 118º 16.17' feet of elevation gain on a fire road. The journey begins in Albert Michelson determined the speed of light by In 1915, an experimental set of check dams was con- Haines Canyon and concludes at an antenna farm, atop the bouncing a beam of light between the highest point structed, to test the effectiveness of this flood control highest point in the City of Los Angeles, 5,074 foot Mt. Lukens. in the San Gabriels, 10,064 foot Mt. San Antonio and method here in Haines Canyon, though the ones you Along the way you will see evidence of the interaction of the Mt. Wilson. will see today date from the 1970s. The purpose of built landscape with the precipitous mountains that surround check dams is to slow down the flow of debris as it the urban fringe of Los Angeles. The trip is strenuous, so The peak you will be ascending, Mount Lukens, was comes down the canyon. This is accomplished by the bring plenty of water. This trail can be very hot during the once known as Sister Elsie peak, named after a nun dams themselves as well as the vegetation that grows summer months, and the summit can be cold and windy. who ran a orphanage for Indians in the area. No re- behind them. The Trailhead cord of Sister Elsie has ever been found and some say N 34º 15.35' W 118º 16.37' that the whole story is a legend. Renamed for early Cabin Sites The trail begins 11 miles northwest of Pasadena. By Angeles Forest supervisor and mayor of Pasadena N 34º 15.999' W 118º 16.012' car: Take the 210 freeway to Lowell Ave.; head north Theodore Lukens, Mt. Lukens hosts an impressive Just to the east and up a small hill from this grove on Lowell Ave.; at the end of Lowell Ave. take the left array of antennas at the top and an excellent example of oak trees are the foundations and fireplaces of fork, which is Day St.; make a right on Haines Can- of flood control structures at its base. This particular several cabins that were built in 1921 and severely yon Ave. (Make sure that you park south of the no- trail was chosen because along the way you will see damaged by a flood in 1929. This flood was caused parking signs.) Proceed to the end of the street and a condensed version of two of the primary ways the in part by the Pavers Rock Company, which had left past the locked gate. The trailhead begins at the end City of Los Angeles interacts with the mountains that tons of rock at the mouth of the canyon, creating an of Haines Canyon Ave. By bus: Take the #90 or #91 surround it: flood control and communications. unintentional dam. The cabins were finally destroyed bus to Haines Canyon Ave. and Foothill Blvd., walk by the 1934 flood. Also in the oak grove is an un- north on Haines Canyon Ave. to Day St.; continue Haines Canyon Debris Basin identified grave of a flood victim. Far enough from directions as above. N 34º 15.41' W 118º 16.36' suburban Tujunga for privacy, the presence of dis- The Haines Canyon Debris Basin lies just inside the carded beer bongs and nitrous oxide canisters marks The San Gabriel Mountains are part of the Trans- boundary of the Angeles National Forest and is part this oak grove as an informal recreational site typical verse Ranges and run east-west, unlike the majority of a vast system of flood control structures that form of urban fringe areas. of mountain ranges in California such as the Sierras, a protective barrier against the often cataclysmic which run North-South. The Transverse Ranges in- forces of rain and erosion that characterize this inter- View of Verdugo clude the San Gabriels as well as the Santa Monica section of wilderness and suburbia. There is a special N 34º 15.917' W 118º 15.667' Mountains, the San Bernardinos, and the Santa Inez significance to this particular debris basin that author From here on, the trail gets steeper, as we depart range near Santa Barbara. All of the Transverse Rang- Jared Orsi explores in his book 'Hazardous Metropo- the urban fringe and enter the wilderness. Continue es owe their height to the San Andreas Fault, which lis.' According to Orsi, in the early 20th century the up the trail and take the fork to the right passing a takes a detour towards the east in Southern Califor- water filled depression you are looking at was once a swinging metal gate. If you go to the left you will nia. The San Andreas, in fact, forces the San Gabriel gravel pit. After the notorious flood of New Year Eve find a fenced area formerly used for beekeeping. mountains up at a higher rate than their erosion. The 1934, it was noticed that, while the check dams that Looking to the south you will see the Verdugo moun- San Gabriel Mountains, of which Mt. Lukens is a you will see up the fire road ahead failed, the gravel tain range which separates the Sunland Tujunga area part, are also a nexus of Southern California's other pit successfully caught much of the debris that came from Glendale and Burbank. On top of the Verdugo two other notorious hazards, fire and flood. down the canyon. While debris basins had been con- range you can see several transmission sites that structed before in other places around the world, this are leased by a wide range of businesses and pub- Abutting Los Angeles, the San Gabriels have always former gravel pit showed the effectiveness of using lic agencies including American Medical Response, been a destination for recreational activities, but debris basins as a flood control strategy in the Los the Metropolitan Water District of Southern Califor- the San Gabriels have also seen many other uses. Angeles area. While most debris basins are fenced nia, the Cities of Burbank and Glendale, Motorola portable radios, and KXTA FM's microwave link to Top of Mt. Lukens Mt. Wilson to name just a few. The Verdugo range N 34º 16.133' W 118º 14.283' presents a large obstacle for some of the transmitters You are now at 5,074 feet, at the highest point in the on Lukens and Mt. Wilson creating what is known as City of Los Angeles, and approximately 23 miles a transmission shadow affecting a large swath of the from the ocean, which, if conditions are right, you !*OURNEYTOTHE4OPOF Los Angeles area. should be able to see. Named for Theodore Lukens, THE#ITYOF,OS!NGELES a close friend of John Muir, Mt. Lukens is one of Rim of the Valley Trail twenty-seven communications sites designated by N 34º 15.833' W 118º 15.267' the Forest Service in the Angeles National Forest, !#ENTERFOR,AND5SE)NTERPRETATION At this point is the Rim of the Valley trail which de- and hosts a wide variety of non-broadcast trans- 7ALKING4OUR scends into the Deukmegian Wilderness Park and mitters including cell phone antennas, microwave, skirts the Dumsmore debris basin. Going down by two-way radio and public safety frequencies. The this trail puts you at a considerable distance from antenna towers are leased by telephone companies, where you began. public safety agencies, and businesses including the Department of Water and Power, the American Red View of Hansen Dam Cross, Aviation Spectrum Resources, Inc., which N 34º 16.033' W 118º 15.250' manages the Aeronautical Enroute VHF Spectrum, To the west, just a mile from the confluence of the Big and many others – everything from taxi companies to Tujunga and Little Tujunga washes you can see the cement truck fleets. Several of the towers are main- Hansen Dam, which was built by the Army Corps of tained by Mountain Union Telecom and American Engineers between 1939 and 1940 to hold mountain Tower Incorporated, companies that build the tow- flood waters away from the City of Los Angeles and ers and lease space on them to tenants who provide the lower portions of the San Fernando Valley. The commercial mobile radio service, cellular service, dam serves a 147 square mile watershed area. Cur- and microwave relays. Mobile Relay Associates op- rently the Hansen Dam, like the Sepulveda Dam to erates a tower providing two way radio. The compa- the west and Whittier Narrows to the east is a large nies that maintain these towers also provide backup recreation area supporting a variety of recreational ac- generators and lease rack space in the cinder block tivities. Incidentally, California has the second largest buildings that you see on the peak. horse population in the country after Texas, with over From here it's all downhill, to Los Angeles. 100,000 horses in Los Angeles County. Most horse owners in urban areas of Los Angeles County live Published by the Center for Land Use Interpretation, 2006. Text by Erik near watershed areas like the Hansen Dam and the Knutzen, from the CLUI exhibit Dissipation and Disintegration: Antennas and Debris Basins in the San Gabriel Mountains.