Rise of the Sierra Madre: A Brief History of the San Gabriel Mountains

Last Friday, 41,000 acres of the Angeles National Forest charred by the 2009 Station Fire reopened to the public. With summer's return, and with newly accessible trails to explore, Southern Californians will soon flock to the San Gabriel Mountainsfor fresh air and mountain scenery.

Stretching from the Cajon Pass in the east to the Newhall Pass in the west, the San Gabriel Mountains are something of a topographic anomaly. Whereas most mountain ranges in California parallel the coasts, the San Gabriels and the other Transverse Ranges, including the San Bernardino, Santa Monica, and Santa Susana, run east-to-west. Geologists credit this crook -- responsible for the prominent jog at Point Conception in the California coastline -- to movement between the Pacific and North American tectonic plates.

About 20 million years ago, the Pacific plate began scraping against the North American plate and broke off a piece of continental crust. Trapped between two plates, the loose block of crust turned 90 degrees clockwise as the Pacific plate dragged it to the northwest. About 5-7 million years ago, part of that block began rising as a mountain range along the Sierra Madre and Cucamonga fault zones, creating the San Gabriels and forming an unusual bend in the otherwise orderly line of coastal mountain ranges.

Since then, the geologically active mountains have been thrust up quickly -- and have been cut back by erosion almost as fast. Much of the Los Angeles metropolis, in fact, sits atop the accumulated sediments washed off the slopes of the San Gabriels.

Today, the mountains trap moist, cool air from the Pacific Ocean and block cismontane Southern California from the hot climate of the continental interior, creating what Carey McWilliams described as "an island on the land." Their rugged slopes have presented a formidable obstacle to travelers and traders, and an existential threat to entire foothill communities, but they have also provided Southern California with a number of productive and recreational uses.

Land of Many Uses

Signs at entrances to the Angeles National Forest, which encompasses much of the mountain range, once declared it a "land of many uses." Indeed, humans have found many reasons to value the San Gabriels for thousands of years.

The mountains offer solitude and seclusion. In the mid-nineteenth century, outlaws sought refuge in the mountains' remote canyons; Southern California's notorious bandit, Tiburcio Vásquez, evaded the authorities for years from his hideout at Chilao (His name might sound familiar because of another hiding spot, the Vasquez Rocks in Agua Dulce). Later, homesteaders would build private hideaways in some of the same canyons that once sheltered cattle rustlers and horse thieves. Among the most notable pioneers of the San Gabriels were Jason and Owen Brown, the sons of abolitionist John Brown, who escaped city life by settling in El Prieto Canyon in the foothills above Pasadena.

That same sense of escape has long drawn hikers, skiers, mountain bikers, and picnickers to the San Gabriels.

Although they don't soar as high as the Sierra Nevada nor offer the same diversity of flora and fauna, the San Gabriels' steep escarpments and deep ravines can challenge experienced adventurers. Even such a tireless trekker as John Muir met his match in the mountains. After an 1877 hike above Eaton Canyon, Muir described the San Gabriels as the place where "Mother Nature is most ruggedly, thornily savage." Chaparral provided the greatest nuisance -- the prickly brush reduced Muir to crawling on his hands and knees for at least a mile -- but the rugged terrain also merited a complaint. "The slopes are exceptionally steep and insecure to the foot of the explorer, however great his strength or skill may be," he wrote.

In the late nineteenth century, as the public's fascination with wilderness grew, rugged entrepreneurs -- followed by railroad titans -- built everything from primitive camps to luxurious resorts deep in the mountains. With tents and beds waiting for them trailside, hikers could plunge into the mountains for a multi-day hike with little more than water and a few basic supplies in their packs. One of the most popular routes was the Tom Sloan Trail, which connected the Alpine Tavern at the top of the Mount Lowe Railway to Commodore Perry Switzer's resort above the Arroyo Seco.

The rise of the automobile and construction of the 66-mile-long Angeles Crest Highway brought an end to this "golden age of hiking" but also opened up the mountains to more casual recreation like day hiking and picnicking.

Mountains as Natural Resources

Perhaps the mountains' earliest use was resource extraction. By 1-500 C.E., Tongva (Gabrielino) people living in the low-lying valleys were making frequent trips into the San Gabriels in search of food, medicine, and tools. Oak trees provided acorns and Manzanita shrubs berries, while yuccas provided the raw material for everything from fishing nets to soap. What couldn't be found locally could be acquired by trade, and the Tongva blazed several trade routes through the mountains. One crossed through the canyon of the San Gabriel River, while others coursed through Millard and Little Santa Anita canyons.

With the arrival of the Spanish in the eighteenth century, the mountains became a source of timber for the San Gabriel Mission and the growing pueblo of Los Angeles. The Old Plaza Church, for example, was built partly with lumber carried by oxen from Millard Canyon. Minerals also drew people into the mountains during Southern California's Spanish-Mexican era. Six years before James Marshall struck gold at Sutter's Mill, Francisco López discovered the precious metal in Placerita Canyon, near present-day Newhall, in 1842. A gold rush ensued, attracting Sonoran miners into the foothills of the San Gabriels.

Resource extraction intensified after the American conquest of 1847. Gold was discovered in Big Santa Anita Canyon, first attracting individual prospectors and later a hydraulic mining outfit, which stripped hillsides in search of the yellow element. Logging also accelerated, and by the 1880s concerns about vanishing forests and the quality of mountain streams and springs amid the denuded hillsides prompted Southern California to reconsider its management of the mountains' national resources. In an 1886 state Board of Forestry report, Abbot Kinney, California's first state forester, pleaded for forest conservation. Naturalists like John Muir and interested parties like San Gabriel Valley farmers and orange growers echoed Kinney's call, and in 1892 President Benjamin Harrison created the San Gabriel Timberland Reserve -- only the sixth such reserve in the nation and the first in California.

With federal protection, unsustainable exploitation would stop, but the mountains would still be managed as a commercial asset to be conserved. Beginning in 1905, the reserve -- renamed the San Gabriel National Forest in 1907 and then again renamed the Angeles National Forest the following year -- would fall under the supervision of the U.S. Forest Service. Rejecting wilderness preservation as a goal, the Forest Service operated according to the conservation ethic espoused by its chief, Gifford Pinchot, who sought to maintain the long-term viability of the mountains' resources.

Now, as the National Park Service considers designating the forest a national recreation area, the federal government is poised to refocus its position on the San Gabriel Mountains toward preservation and environmental justice.