areas going as long as 100 years without fires and others burning more frequently. It has been estimated the chaparral plant community can persist over the long term only with a fire frequency at a given site of no shorter than several decades, or perhaps longer, although there is variability in the tolerance of different species. Repeated shorter intervals between fires promote so-called "type conversion," in which the shrubby species are replaced by grasses, particularly non-native grasses, and other weedy species. The Verdugo Mountains have been subject to repeated wildfires in historical times. Major occurrences in the twentieth century include the December, 1927 Burbank Canyon Fire, which started in Haines Canyon in the San Gabriel Mountains and burned south into the range, consuming approximately 100 homes in Burbank's Sunset Canyon. The La Tuna Canyon Fire of November, 1955 burned over almost the entire western portion of the range, ultimately destroying approximately . The Whiting Woods Fire of March, 1964, started by a power line downed by high winds, burned from the northern edge of the range southward over to crest to consume homes in Glendale. A fire in November, 1980, also called the La Tuna Canyon Fire, burned in the northern and western portions of the range. Since 2000, three major fires have occurred in the Verdugo Mountains. In September, 2002, the Mountain Fire burned over two days approximately above Glendale, largely on the southern side of the range. The Harvard Fire started on September 29, 2005, and consumed both north and south sides of the range north of Burbank during a six-day period. In September, 2017, the La Tuna fire started north of the Verdugos, jumping Interstate 210 forcing the closure of it, burning both the north and south face of the ranges. The fire ultimately destroyed four homes and of land. Beginning in 1921, the Los Angeles County Fire Department began a county-wide program of building fire breaks (or more properly, fuel breaks) to slow the spread of fire, and by 1923 the initial breaks had been constructed in the Verdugos. In 1934, the City of Glendale built a 60-foot lookout tower on Verdugo Peak, which was staffed with an observer until it closed in the mid-1950s. In order to conduct the work necessary to build fire breaks and roads, temporary construction camps were located throughout the fire-prone areas of the county. In the Verdugo Mountains, Construction Camp