Geology

Human

"In addition to guiding their ecosystem, the Tongva managed their economy by blazing well-worn trade routes into the mountains to barter with local tribes. The people of Asuksangna followed a route that led up the West Fork of San Gabriel Canyon and scaled the mountains. A complex system of footpaths led to major landmarks, like Mount Wilson, Red Box Saddle, Millard Canyon, and the camps of the Chilao backcountry. These gathering sites set the stage not only for an exchange of goods, but also functioned as a place to swap songs, gossip, embrace distant family, and meet youth from other mountain areas. Few groups continued north as well, crossing the entire transverse range and dropping into the blazing sands of the Mojave Desert." -Daniel Medina

Timeline

1,700,000,000 B.P. – Rocks found on the eastern slopes of present day San Gabriel Mountains begin to form under an ancient sea
65,000,000 B.P. – San Gabriel Mountains begin to form
5,000,000-1,800,000 B.P – L.A. Mountains forced up while sea level decreases
100,000 B.P. – Los Angeles rises from the sea forming it's present day shoreline
13,050 B.P. – Beginning of Clovis culture
11,000 B.P. – Humans begin settling in coastal areas of what is now the Los Angeles area
10,220-10,250 B.P. – La Brea Woman dies in the La Brea Tar Pits area of Los Angeles
10,000 B.P. – Ice-age animals extinct in Southern California
6,000 B.P. – Humans abandoned the L.A. area
3,000 B.P. – Chumash resettle
1,000 B.C.E. to 700 C.E. – Uto-Aztecan (Shoshonean) peoples enter the L.A. Basin
525 – The Wally Walden tree is born!
1479 – Treaty of Alcáçovas
1492 – First expedition of Christopher Columbus
1521 – Hernán Cortés conquers the Aztec Empire
1542 – Juan Rodríguez Cabrillo reaches “Bahía de los Fumos,” modern-day San Pedro Bay
1565 – First Spanish mission in North America established in St. Augustine, Florida
1588 – Defeat of the Spanish Armada
1610 – Santa Fe, New Mexico established by Spain
1697 – First mission on the Baja California Peninsula
1760 – Toypurina born in the village of Jachivit
1767 – King Charles III of Spain orders the expulsion of the Jesuit order from all Spanish territories
1769 – Mission San Diego de Alcalá founded
1771 – Kizh (Tongva) slaves build Misión de San Gabriel Arcángel
1775 – Original Mission San Diego church burned down during Indigenous rebellion
1781 – Los Angeles founded
1785 – Toypurina leads Indigenous rebellion against Mission San Gabriel
1787 – Baptism of Toypurina
1797 – Mission San Fernando Rey de España founded
1821 – Declaration of Independence of the Mexican Empire
1848 – Treaty of Guadalupe Hidalgo
1850 – California becomes the 31st state
1851 – Mormons make camp at Lytle Creek
1854 – The Mormon settlement of San Bernardino is incorporated
1859 – Victor Beaudry and Damien Marchessault build an icehouse in a canyon
1892 – President Benjamin Harrison establishes San Gabriel Timberland Reserve (future ANF)
1893 – Shortcut Trail
1893 – The San Bernardino Forest Reserve established
1904 – Mount Wilson Observatory founded by George Ellery Hale
1908 – The Angeles National Forest (ANF) established
1911 – John Mendenhall born
1913 – Captain Loomis begins his homesteading journey
1915 – ANF becomes first national forest to require campfire permits
1916 – Cornelius Birket Johnson kills the last grizzly bear in Southern California
1918 – World War I Ends
1919 – Ravenna and San Gabriel fires burn a combined 130,000 acres in the ANF
1924 – Edwin Hubble uses the Mount Wilson Observatory to prove that Andromeda is its own galaxy and not part of the Milky Way
1929 – Construction begins on the Angeles Crest Highway
1930 – First belayed climb in the Sierra Nevada (John Mendenhall on Laurel Mountain)
1932 – Cragmont Climbing Club becomes the Rock Climbing Section (RCS) of the Sierra Club
1933 – Glen Dawson, Dick Jones, and John Poindexter teach belaying at Bee Rock and Eagle Rock
1933 – 27 black bears introduced to San Bernardino and San Gabriel Mountains
1934 – Art Johnson chairs the first Southern California RCS chapter
1935 – Royal Robbins is born
1938 – Los Angeles flood destroys Camp Baldy and causes destruction across the basin
1939 – Lynn Newcomb Sr. and his sons, Ren and Lynn Jr., build Newcomb’s and start Mt. Waterman Ski Hill
1941 – Mt. Waterman opens to the public (first chairlift in the Angeles)
1945 – World War II Ends
1952 – Royal Robbins climbs the world’s first 5.9 at Tahquitz
1954 – First chairlift at Kratka Ridge constructed
1956 – Angeles Crest Highway officially opens
1957 – John Gill climbs V7 on Red Cross Rock in the Tetons
1959 – John Gill climbs V9 on Red Cross Rock in the Tetons
1964 – Congress establishes the National Wilderness Preservation System
1966 – Loop Fire burns 2,028 acres and takes the lives of 12 firefighters
1983 – John Bachar imports 265 pairs of Boreal Fires to sell at the Yosemite Mountain Shop
1985 – Southern California RCS of the Sierra Club ends
1986 – Southern California Mountaineers Association (SCMA) is founded
1988 – Paul Hellweg and Nathan M. Warstler publish Climber’s Guide to Southern California
1990 – Falcon publishes Craig Fry’s Southern California Bouldering Guide
1991 – John Sherman invents the V-scale
1995 – James March climbs Blank Generation (V9)
1999 – Rock & Ice publishes “Seeking Refuge: Higher Ground Bouldering in Los Angeles County,” James March’s guide to Horse Flats
2005 – Williamson Rock is closed
2009 – Station Fire burns 160,577 acres, 209 structures, and takes the lives of 2 firefighters
2014 – San Gabriel Mountains National Monument established by President Barack Obama
2016 – Glen Dawson passes away at the age of 103!
2017 – Matthew Dooley, Dimitrius Fritz, and William Leventhal author Los Angeles County Bouldering
2020 – Bobcat Fire burns 115,796 acres and 170 structures
2024 – Bridge Fire burns 56,030 acres and 81 structures
2025 – The Fang breaks