Mountain High

Big Pines is an unincorporated community in Los Angeles County, California, United States. It is in the Angeles National Forest, San Gabriel Mountains.

Table Mountain Observatory (TMO) is an astronomical observation facility operated by NASA's Jet Propulsion Laboratory (California Institute of Technology). It is located in Big Pines, California, in the Angeles National Forest near Wrightwood, north-northeast of Los Angeles, California. TMO is part of JPL's Table Mountain Facility (TMF). The larger site hosts a number of non-astronomical projects. The site was first used by the Smithsonian Institution in 1924, which conducted atmospheric, solar, and astronomical observations for many years. JPL took over the lease in 1962. The observatory conducts high-precision astrometric observations to support NASA and international spacecraft mission navigation, confirmation and recovery of near-Earth objects such as comets and asteroids that may potentially impact the Earth, and technology development. The main-belt asteroid 84882 Table Mountain was named in honor of the observatory.

The Clinton B. Ford Observatory (Wrightwood) (Observatory Code 674) is an astronomical observatory that is associated historically with the American Association of Variable Star Observers (AAVSO). The observatory is located near the border of the Angeles National Forest and the San Bernardino National Forest near Wrightwood, California (United States). It was founded by the late astronomer Clinton B. Ford. In 2012, the Clinton B. Ford Observatory was donated to the Los Angeles Astronomical Society (LAAS). On September 10th, 2024, the Bridge Fire rapidly approached and completely destroyed the observatory.

Jackson Lake is located in the Angeles National Forest in Los Angeles County, California, at an approximate elevation of 6,000 feet (1,800 m). The lake is located in a day-use area in the San Gabriel Mountains National Monument. Jackson Lake is located on the USGS 7.5 minute quadrangle map entitled "Mescal Creek". Jackson Lake is a sag pond located on the San Andreas Fault, a strike slip fault that runs the length of California. Sag ponds are created when the fault action creates a depression in the land where rainwater or snowmelt can collect. The sag pond for Jackson Lake consists mostly of snowmelt from the San Gabriel Mountains. Jackson Lake has been the site of drownings due to the thin ice which can cover the top portion of the lake in colder months but may not be strong enough to support human weight. Popular activities for the lake area include fishing, swimming, picnicking, and kayaking.

Pine Mountain Ridge (or simply Pine Mountain) is a massif of the Transverse Ranges located in northern Ventura County, and entirely within the Los Padres National Forest. The ridge is a large block of Matilija Sandstone, and reaches some of the highest elevations in the southern Transverse Ranges. The north slope of the ridge is part of the Sespe Wilderness. Major peaks on the ridge include, from west to east, Reyes Peak, Haddock Peak, and Thorn Point.

The Big Horn Mine is a defunct gold mine located at the headwaters of the east fork of the San Gabriel River off Highway 2 at Vincent's Gap in the Angeles National Forest in Southern California, U.S. It was once touted as the “granddaddy” of the San Gabriel Canyon mines.

Mount Baden-Powell () is a peak in the San Gabriel Mountains of California named for the founder of the World Scouting Movement, Robert Baden-Powell, 1st Baron Baden-Powell. It was officially recognized by the USGS at a dedication ceremony in 1931. It was originally known as East Twin or North Baldy.

Mount Burnham is one of the highest peaks in the San Gabriel Mountains. It is in the Sheep Mountain Wilderness. It is named for Frederick Russell Burnham the famous American military scout who taught Scoutcraft (then known as woodcraft) to Robert Baden-Powell and became one of the inspirations for the founding of the Boy Scouts. Mount Burnham was officially recognized by the USGS at a dedication ceremony in 1951. It was original known as (West Twin) "North Baldy Mountain". The peak is within Los Angeles County, about 16 miles (26 km) north of Glendora, and 66 miles (106 km) from Los Angeles. In 1956, Mount Burnham was added to the list of Signature Summits by the Hundred Peaks Section of the Sierra Club.

The 1812 San Juan Capistrano earthquake, also known simply as the Capistrano earthquake or the Wrightwood earthquake, occurred on December 8 at 15:00 UTC (07:00 a.m. local time) in Alta California. At the time, this was a colonial territory of the Spanish Empire. Damage occurred at several of the missions in the region of Pueblo de Los Ángeles, including Mission San Gabriel Arcángel and Mission San Juan Capistrano, where 40 parishioners were killed during the collapse of a church at an early morning service. Tree-ring and paleoseismic evidence show that there is a strong likelihood that the earthquake originated along the Mojave segment of the San Andreas Fault near Wrightwood, but other faults have been suggested as the cause. Several studies in the 1980s placed the shock along the southern Newport–Inglewood Fault near the zone of highest reported intensity. This fault is near the coast and the most significant damage at the missions, but later work at trench sites along the San Andreas Fault excluded it for this large-to-very-large shock. Dynamic rupture modelling enabled another proposal in the 2010s involving a dual-rupture scenario with both the San Andreas and San Jacinto Fault Zones. Each of these studies worked with limited data, and the effects of the shock and various fault rupture details led to Mercalli intensities of VII (Very strong) to IX (Violent) being proposed. Magnitudes from 6.9 Mla on the low end to 7.5 Mw on the high end were also presented.

The Bridge to Nowhere is an arch bridge that was built in 1936 north of Azusa, California, United States in the San Gabriel Mountains. It spans the East Fork of the San Gabriel River and was meant to be part of a road connecting the San Gabriel Valley with Wrightwood, California.

Throop Peak ( TROOP) is a 9,142 feet (2,786 m) peak of the San Gabriel Mountains, in the San Gabriel Mountains National Monument and Angeles National Forest, in Los Angeles County, California. The high peak provides views of both the Mojave Desert and the Los Angeles Basin all the way to the ocean. The peak was named for Amos G. Throop, founder of Caltech, formerly called Throop College. The peak marks the northwestern boundary of the Sheep Mountain Wilderness.

Lookout Mountain in Los Angeles County, California, is a 6,812-foot (2,076 m) peak on the shoulder of Mount San Antonio ("Mount Baldy"). Albert A. Michelson used the peak to measure the speed of light in 1925–1929. For him to do so, the United States Coast and Geodetic Survey in 1923 established a 21.5-mile (34.6 km) baseline with an accuracy of 1 part in 11 million from Pasadena, California, at the base of Mount Baldy roughly to Rancho Cucamonga at the base of Mount Wilson. It may have been the most accurate baseline ever determined at the time. The Coast and Geodetic Survey then used the baseline to triangulate the distance to the Mount Wilson Observatory, with a distance error of about 1 part in 5 million, and Michelson measured light travel time between the stations with a rotating mirror apparatus. The concrete piers on Lookout Mountain used for the Michelson observations still exist.The first fire lookout in the Angeles National Forest was built on Lookout Mountain in 1914 and stood until it burned in 1927.