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Who Knew? The History of Glen Canyon


Near the geographic center of San Francisco (population 850,000+) lies a rugged canyon of Franciscan chert and some Franciscan greenstone with precipitous slopes and rocky parapets rising 350 feet above its floor. This 70 acres of open space is about one mile long from the southern slopes of Twin Peaks southward to Martha Hill, and about one-third mile wide between Miraloma Park to the west and Diamond Heights and Glen Park to the east. A full 60 acres of the canyon, including O’Shaughnessy Hollow on the west side of O’Shaughnessy Boulevard, has been designated a Significant Natural Area. Though the main entrance is accessed from the south at Glen Park, the San Francisco Redevelopment Agency declared Glen Canyon to be a part of Diamond Heights in 1950.


Glen Canyon is partially bisected by Islais Creek, whose banks are graced with willow trees, wild cherry, numerous wildflowers, and coastal scrub. Walk softly and you may be lucky enough to encounter wildlife such as the great horned owl, red tail hawk, raccoon, skunk, coyote, the San Francisco forktailed damselfly, or the endangered San Francisco garter snake and Mission blue butterfly. To the casual eye, most of Glen Canyon seems untouched by development.


However, nothing could be further from the truth. Despite its natural appearance, Glen Canyon has been the site of extensive activity, highlighted below. A few links to trusted external resources provide more in depth information.


The story of Glen Canyon begins thousands of years ago with the Native American Muwekma Ohlone. Before the arrival of the Spanish, an estimated 10,000 people had lived in tribelets for thousands of years from Point Sur north to San Francisco, each with its own language. The Yelamu tribelet was located on the northern tip of the San Francisco peninsula and lived in several permanent villages both on the Pacific coast and the Bay side. The village of Amuctac was situated along the Islais Creek wetlands that once extended east of Highway 101 from the Interstate 280 interchange. As hunters and gatherers, the Ohlone enjoyed the abundant and fertile natural resources of the area, including fish, mussels, and crab from the Bay, and seeds, grasses, berries, and nuts from the land. During certain seasons, the Yelamu would range farther away from their villages to gather favorite delectables, likely visiting Glen Canyon and the surrounding slopes. 

It’s hard to believe that only 165 years ago, the residents of early San Francisco shared the landscape with herds of elk, antelope, black tail deer, mountain lion, wolf, and grizzly bear. The next time you are walking through Glen Canyon, imagine what the scene must have been like. Read more.

Islais Creek (pronounced "Is-Liss" or "Is-Lay") is believed to be a word from the Ohlone language for the wild cherries that grew creekside. Originating at the southern base of Twin Peaks, with tributaries from the northern slopes of San Bruno Mountain and southeastern Bernal Hill, it is the largest creek in San Francisco.


It was initially named "Du Vrees" Creek on the U.S. Coast Survey Map of the City and County of San Francisco, 1858. Little is known about this individual. According to a legal summary by the City Attorney of San Francisco for a case against the Southern Pacific Railroad in 1909, "Du Vrees" was actually Captain Jens C. De Vries, who had owned property in the area being contested bordering the creek in 1853. On June 1 the previous year, a notice in the Daily Alta California had announced the dissolution of a butchering and marketing business between De Vries and J.D. Morgan. De Vries is listed in Langley's San Francisco Directory for the Year Commencing June, 1859 as living on Folsom Street. In the 1860 U.D. Federal Census, a "J De Vries," 37, of San Francisco is noted as having been born in France and employed at the time as an auctioneer. Afterwards, he seems to disappear from public records. It will require more research to determine if De Vries was the first proprietor in the area that would become known as “Butchertown,” near the mouth of Islais Creek.


Once 3.5 miles long above ground and as much as eight feet deep in Glen Canyon, Islais Creek was providing 85% of San Francisco’s drinking water by the late 1880s. More than once, proposals to dam Glen Canyon to create a reservoir were made, the first time in 1856. Much of the creek was forced underground in the 1920s and only a short portion remains daylighted in Glen Canyon. When you are driving along Interstate 280 between Monterey Boulevard and the Highway 101 interchange, you are essentially driving on top of Islais Creek.

Once the Spanish missionaries and soldiers arrived in 1776, the Ohlone and other Native Americans throughout California were being decimated by disease, experiencing reduced birth rate because of separation by gender, and being directed away from practice of their traditional culture. Those who survived worked the land and tended to the livestock of Mission Dolores, primarily cattle that free-ranged across the slopes of the peninsula. With an estimated 50,000 heads of cattle owned by the Mission in the 1830s, it is quite likely they ranged among all the hills surrounding Glen Canyon. Cattle raising and dairy would become a tradition of Glen Canyon that would continue through the Rancho period to just before World War II. Read moreAnd even more.

Islais Creek
Spanish Mission Period, Dairy History

The most prestigious awards in the world, the Nobel Prizes in Peace, Chemistry, Physiology or Medicine, and Literature, are awarded annually in Stockholm, Sweden. These rewards exist today because of a powerful innovation by Alfred Nobel in the 1860s: dynamite. Each time we hear the Nobel Prizes announced, we should think of Glen Canyon. Why? The very first factory for the manufacture of dynamite, personally licensed by Alfred Nobel, was located here in Glen Canyon.


The site was designated as California Historical Landmark No. 1002 but was without a plaque commemorating its history for 27 years. Read more about the history of Alfred Nobel and the Giant Powder Company in Glen Canyon, and how the Glen Park Neighborhoods History Project was able to partner with the Native Sons of the Golden West, San Francisco Recreation and Parks Department, and the California Bell Company to place the plaque for California Historical Landmark No. 1002 (scroll to see MISSION ACCOMPLISHED!).

Giant Powder Company
Glen Park and the Mission Zoo
Islais Creek
Spanish Dairy
Giant Powder
Glen Park Zoo

This is likely the rowdiest and most outrageous period in the history of Glen Canyon. Once dubbed “The Sensation of the Century,” the history of the Mission Zoo had largely disappeared from the annals of San Francisco history. It’s a wild story that includes accusations and name-calling among prominent men (including the first president of Stanford University), a fistfight outside of the chambers of the Board of Supervisors that was broken up by a mayor, class conflict over rights to have a “breathing spot” and a chance for increased home values (a case of blue collar workers of Glen Park, the Fairmount Tract, and Sunnyside versus the wealthy elite many of them worked for), a Spanish castle, hot air balloons navigated by parachuting, acrobatic aeronauts (including aviation pioneer and Fairmount Heights resident Daniel J. Maloney), tightrope walkers, and ranging elk (think Elk Street), a bear pit, a seal pond, plus numerous vaudevillian acts and events. Thousands would trek to the park each week, which was exactly the plan. The whole project was conceived by real estate agent A.S. Baldwin of Baldwin & Howell, who wanted to attract prospective home buyers for his new tract known as Glen Park Terrace. Read more in a six-part series: Part I, Part II, Part III, Part IV, Part V, and Part VI. Learn more about how the residential district of Glen Park got its name.

There is little evidence of the earthquake refugee camp that was raised in the area of Glen Canyon (in addition to the city-owned, future site of the Glen Park School) following the 1906 Great Earthquake and Fire, and it is not listed among the official earthquake camps maintained by the U.S. Army throughout the City. However, in an article appearing in the San Francisco Call on April 21, 1906, it was announced, "The owner of Glen Park will care for the homeless on the grounds [the "grounds" meaning 140 acres in and around today's recreation area], where there are supplies and water". Another camp was located at the then empty block of today's Glen Park School. However, an article in the San Francisco Chronicle on February 3, 1908, provides us with a clue. The population explosion in the new district after the earthquake would help make Glen Park a hub of the San Francisco suffrage movement that would lead to a resident's leadership in the first march for suffrage in the United States.

Earthquake Refugee Camp
Earthquake Camp
Alms Road
(also the Gum Tree Girls Trail)
Alms Road
The Red Barn
Red Barn

The heyday of Glen Park and the Mission Zoo under Baldwin was short-lived, actively promoted from late 1897 through 1900. Yet, activities in the area did not cease. At least one oral history indicates wild zoo animals were still in the canyon as late as 1909. In 1907, the Crocker Estate Company developed the area as a picnic grounds for private use, offering a baseball diamond, and basketball and tennis courts. The Glen Park Pavilion, known by locals as the Red Barn and located near the site of today’s Recreation Center, housed a bowling alley and dance hall. Local organizations would rent the facilities weekly and announce their excursions in the newspaper. In the 1910s, the California National Guard would use the canyon for sham battles and set up a rifle range, reasoning that, “The contour of the park is such that the bullets are sent against the targets over the picnic grounds without endangering the safety of persons unless they be in the low lying valley.” The City purchased the land from the Crocker Estate Company in 1922, returning the canyon to public use. Sadly, the Red Barn burned down in 1932. Today, Glen Canyon has been offering continous recreation opportunities for the past 120 years!

Read more about the popularity of picnicking among San Franciscans at the turn of the century.

Alms Road appears on the earliest maps of the region, perhaps the remnant of a trail used by the Yelamue tribelet of the Muweka Ohlones as they made their way for hunting and gathering up Islais Creek from their permanent villages at the mouth of the creek at San Francisco Bay. It was also likely used as access to “milch ranches” (dairy farms) in Glen Canyon as early as 1860, and perhaps earlier during the Mission Period.  Alms Road still exists today as the main path in Glen Canyon. But why do locals call it “Alms” Road? Since the time of A.S. Baldwin, there had always been a plan to connect Glen Park to Golden Gate Park in a grand loop via the Alms House, today’s Laguna Honda Hospital. With the help of Berkeley landscape architect George Hansen, Baldwin proposed a route in 1897 that would connect Glen Avenue (today’s Chenery Street between Diamond and Elk) to Alms Road (a remnant of the entry of Glen Avenue into Glen Canyon still exists as a narrow path just north of the tennis courts). Traveling north on Glen Canyon's Alms Road, Baldwin’s plan would connect travelers to another Glen Avenue that was to emerge near the intersection of O’Shaughnessy Boulevard and Portola Drive. From there, the route would follow Woodside to Laguna Honda Boulevard to 7th Avenue and into Golden Gate Park. Daniel Burnham’s City Beautiful plan for San Francisco in 1905 proposed a similar route. The northern Glen Avenue emerging near Portola Drive would appear on maps through 1915. Read more

Rec Center
Gum Tree Girls
Glen Park Recreation Center
Gum Tree Girls and the Freeway Revolt

Following the loss of the Red Barn, the City made plans to rebuild. More people wanted to use the City’s parks, and the San Francisco Playground Commission wanted to meet the public’s demand. The Works Progress Administration (later the Works Projects Administration, WPA) was created by President Franklin D. Roosevelt to create jobs for those who had none during the Great Depression. It was through this program that our current Glen Park Recreation Center was constructed. Several new “clubhouses” were built throughout the City, accommodating needs for places to meet, tell stories, play games, participate in art activities, and watch performances. William G. Merchant, a protégé of Bernard Maybeck, designed the structure. Merchant was well known for his work on Maybeck’s Palace of Fine Arts for the Panama-Pacific International Exposition in 1915. He also developed the Temple of the East and the Pacific Building at the Golden Gate International Exposition on Treasure Island in 1939. Other significant buildings by Merchant include the Acme Brewing Building, the Sailor’s Union of the Pacific, and the Pulgas Water Temple of the Hetch Hetchy system in Woodside. The recreation center was completed in 1938.

[Read the complete history: Wonder Women! Glen Park's Gum Tree Girls, Minnie Straub Baxter, and the San Francisco Freeway Revolt]

Imagine if an elevated viaduct freeway, initially named the Circumferential Expressway, were to run right over the baseball diamond and Glen Canyon Park Recreation Center, north through Glen Canyon adjacent to O'Shaughnessy Boulevard, tunnel under Portola Drive, emerge at Laguna Honda Boulevard, travel along 7th Avenue, tunnel under Golden Gate Park to again emerge on Park Presidio, only to provide a quick connection from the Bayshore (U.S. Highway 101) and Southern (Interstate 280) freeways with the Golden Gate Bridge. First conceived in 1948, the San Francisco Freeway Plan would have created new freeways crisscrossing and circling the City. Were it not for the fortitude and gumption of some Glen Park women, Glen Canyon as we know it today would not exist. Several attempted assaults were made on the canyon beginning in the 1950s when highway development reigned supreme. The California Highway Department proposed several new freeways crisscrossing the City, nearly all quaffed by neighborhood activism. Some, such as the now demolished Embarcadero Freeway and the Fell Street terminus of the Central Freeway, were partially built but soon stopped from extending further into neighborhoods when The People won the battle. The absurdly named “Circumferential Freeway” was the first route proposed through Glen Canyon, followed by the Crosstown Freeway.


Minnie Straub Baxter led the initial effort to stop the freeways in 1958, traveling to Sacramento to present a three-minute speech to the California legislature. After resident Zoanne Theriault Nordstrom came across a highway worker digging a test bore for “a new viaduct” through Glen Canyon in 1965 and declaring, "The hell it is!", she along with Joan Seiwald and the late Geri Arkush created the Save the Park Committee. City Engineer Clifford Geertz dubbed the three women as the “Gum Tree Girls” while dismissing their opposition to the freeway plan. Learning how to work the political system on-the-fly, partnering with other activist residents and politicians (including future Mayors George Moscone and Willie Brown, plus future Supervisor Sue Bierman) throughout the City, and bolstered by rising gas prices and a burgeoning environmental movement, the Gum Tree Girls finally defeated the plan for good in 1970, 12 years after it was first proposed. 

Named for the non-native eucalyptus trees that surround the designated camp area, Silver Tree Camp has been a cherished activity for children not only of the Glen Park area but for children across the City. Established in 1945, the camp still provides outdoor activities in a wooded setting like no other in San Francisco. Children explore the mysteries of the canyon, enjoy crafts, story-telling, and campfires. [Note: otherwise, campfires and barbeques are not permitted in Glen Canyon.] Many Silver Tree Day Camp graduates seem to fondly remember the scrumptious camp meals served in earlier days. Read more.


The Glenridge Cooperative Nursery School holds classes in the Silver Tree building in Glen Canyon, constructed around 1960. A unique, child-centered learning program with active parent participation, the school has been in operation since 1970.

Silver Tree Day Camp, Glenridge Co-op Nursery
Silver Tree, Glenridge
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