The Environmental History of Saint Mary's College

From the formation of its geological structure millions of years ago to the campus' growth in the 1970s, the environmental history of Saint Mary's College is a fascinating one. Professor Gretchen Lemke-Santangelo's article "The Environmental History of Saint Mary's College," illustrates the vast changes of our local natural history. Download the PDF here.

The land beneath the College rests on the border of the massive American and Pacific plates, slabs of the earth’s crust that ride atop molten rock. Over the last one hundred million years these plates have collided, pushed apart, and ground or slipped against each other, creating topography of varied elevations. Local faults, including the San Andreas, Hayward, and Calaveras, mark the zone of plate convergence. As the landscape folded, warped, subsided, and thrust upward, wind and rushing water carved additional contours. Rivers and streams, fed by much more rainfall than in our time, deposited non-marine sediment in low- lying areas. Another type of sedimentary rock, containing seashells and other remnants of marine organisms, indicates that ocean waters periodically covered the heaving landscape.

Redwoods in Canyon, just outside present-day MoragaBetween thirty million and ten thousand years ago, the land gradually assumed more familiar features. The coastline, carried north along the Pacific plate from Baja California, slid into place near its present location. Next, the great Sierra Nevada range (which is still rising), and younger coastal ranges emerged. The San Francisco Bay, our most recent landmark, took shape after the first people had arrived, and as the last ice age came to a close and contributed to rising sea levels. As the great North American glaciers retreated (beginning about twenty thousand years ago), the climate became warmer and drier. Older plant and animal species, like the mammoth, saber-toothed cat, three-toed horse, camel, and giant sloth, slipped into extinction. Redwoods, however, survived in isolated pockets—including those in nearby Canyon. New species evolved, providing sustenance for the area’s first human residents.

Beginning more than ten thousand years ago, Saint Mary’s and neighboring Moraga became home to a succession of people who subsisted upon the region’s natural bounty of plant and animal foods. Saclans, relatives of Miwoks and the most recent in a series of indigenous inhabitants, settled the area around 700 A.D. Like their predecessors, they found ample game (elk, deer, antelope, rabbits, beaver, grey squirrels, and wood rats, waterfowl) and an abundant supply of plant foods including the protein-rich acorn. Waterfowl, winging along the great Pacific flyway, darkened the daytime skies. Herds of elk and antelope roamed the grasslands in such numbers that they were likened to great herds of cattle by European explorers and settlers. During annual runs, the local streams filled with salmon and steelhead—their bodies so thick that they transformed the water into a seemingly solid, shimmering mass.

Like other early Californians, Saclans undoubtedly modified the landscape, using fire to burn brush and encourage the growth of grasses that attracted deer, elk and antelope. They also scattered seed to encourage the growth of favored plants near settlements, and pruned old growth from oaks and other seed/fruit-bearing plants. However, their long tenure on the land suggests a sustainable lifestyle, one that had minimal ecological impact. Indeed, Saclans regarded their plant and animal co-inhabitants as spiritual equals entitled to respect and even worship. They saw themselves as part of a sacred, well-ordered universe where no single being claimed dominion over others. Even their competitors or potential natural enemies—grizzly bears, wolves, mountain lions, coyotes, foxes, bobcats, bald eagles, giant condors, and other large raptors—inspired reverence and awe. Mission Dolores, 1851

The Saclan’s world shifted dramatically in 1776 with the arrival of Father Francisco Palou, Lt. Jose Moraga, sixteen soldiers, and a small band of prospective settlers of mixed Spanish, Indian and African descent. The travel-weary party soon established a settlement, mission, and presidio in what would later become San Francisco. Although situated across the bay, these new arrivals altered the environment in and around Saint Mary’s. They introduced non-native plants and animals, including European grasses, which gradually displaced many indigenous species over an ever-widening area. They also introduced diseases that had a devastating impact on the non-immune Indian population. The Coastanoans or Ohlones, who lived close to the mission, were the first victims of foreign microbes.  As many resisted incorporation into the mission system and sought refuge across the bay, they spread diseases to the Saclans and neighboring triblets. By 1794, following massive epidemics and accompanying cultural and economic disruption, a few Saclans abandoned their villages and opted for life across the bay at Mission Dolores. A majority, however, remained, attempting to follow their traditional way of life in shadow of a growing foreign presence.

In 1835 Joaquin Moraga, grandson of the co-founder of the San Francisco mission and presidio, and his cousin Juan Bernal acquired Saclan territory by petitioning the Mexican Assemby for a land grant. Saclans, with the stroke of a pen, were thus faced with a traumatic choice: either remain as landless, dependent laborers of Bernal and Moraga, or seek refuge inland with other tribes. Those who remained on the Moraga ranchero raised cattle for a burgeoning trade in hides and tallow and performed domestic chores within the household. In the meantime, environmental change, initiated by settlers and missionaries across the bay, accelerated.  Heavy trampling and close grazing of Moraga’s livestock aided the displacement of native plants. Hills, once green all year round with perennial bunch grasses, turned gold during the long dry season as European annuals took root. Antelope and elk, unwelcome competition on the grasslands, were killed for sport and meat. And the large predators—the grizzly, wolves, and mountain lions—met a similar fate. Streams, muddied by livestock, became less hospitable to salmon and steelhead.

In 1848, through the Treaty of Guadalupe Hidalgo, Mexico ceded California to the United States. This development, along with the Gold Rush of 1849, brought thousands of land-hungry Anglo-American settlers to the region. Moraga, like other Mexican land grant holders, was required to prove that he had title to the land—a lengthy, costly legal process that bankrupted many Californios. While still in the process of establishing the legality of his claim, Moraga had to contend with Anglo squatters who simply settled on his land without permission. For example, in 1851, after lumbermen illegally stripped his redwood groves to provide timber for growing settlements, Moraga cut his losses and sold Redwood Canyon to the future founder of Layfayette, Elam Brown. Despite such pressures, Moraga still owned most of his original rancho at the time of his death in 1855. Thereafter, the land changed hands as his heirs sold or lost parcels to foreclosure. Over the next fifty-five years a series of investors held title, renting or leasing to ranchers and farmers while hatching various schemes to subdivide and develop the property. This led to additional changes on the land: clearing redwoods, oak, riparian woodlands, and chaparall for timber and to make way for farming and grazing; draining, damming, and diverting streams and wetlands for irrigation and flood control; slaughtering remaining elk, antelope, and grizzly bear populations to eliminate threat and competition with livestock; and importing (accidentally and intentionally) non-native plant and animal species.  As a consequence, many native species disappeared altogether, while others struggled to adapt to changed environmental conditions.

1927: The Saint Mary's College Construction SiteBetween 1912 and 1923, James Irvine, a Southern California entrepreneur, acquired title to almost all of the original rancho. His Moraga Company created an agricultural empire, hiring tenant farmers and sharecroppers to cultivate orchard crops (pears, walnuts, and peaches), grain and fodder, tomatoes, corn, beans, and squash. His tenants, in what a Collegian editorial would describe as “a medieval institution with modern methods,” paid rent to Irvine in crops, and exercised little control over day-to-day farm operations.  Saint Mary’s land was either too marshy or steep for farming and, thus escaped impacts associated with crop production. But cattle grazing continued, contributing to soil erosion and compaction, stream siltation, and destruction/displacement of native plant and animal communities.

In 1913, with the completion of the Oakland & Antioch Railroad, Irvine hatched various schemes to subdivide his non-agricultural property into saleable suburban housing tracts. His offer of 100 acres of free land to Saint Mary’s in 1927, brokered by two College alumni associated with the railroad and Moraga Land Company, was intended to advance these ambitions. The Brothers who inspected the site in the spring of 1927 were not impressed. Alighting from the train at the edge of the proposed site, the Brothers looked out over a marshy basin that received water from the surrounding hills. Nonetheless, they accepted the offer and purchased additional acreage.

The Brothers broke ground on May 15, 1927, the feast of St. John Baptist de la Salle, as Archbishop Hanna prayed, “May the buildings which grow from this earth house the ideals that have gone into its planning.” And grow they did. First, however, contractors dug miles of trench to divert natural run-off, and for sewage, gas, steam, electricity, and phone lines. Las Trampas creek, home to salmon and trout, was dammed to create Lake La Salle--a water supply for the College. Fifteen mission-style buildings followed, transforming a natural marsh into what Brother Z. Joseph characterized as “a veritable thing of beauty.”

In 1941, as the war siphoned off its student body, the College offered its facilities to the Navy for a pre-flight training school. To accommodate its recruits, the Navy constructed barracks, a field house, swimming pool, mess hall, rifle range, infirmary, and boxing pavilion, expanded gas, electrical, and sewage capacity, and ran a two-mile water main that connected the campus to the East Bay Municipal Water District’s plant in Lafayette. The Navy departed after the war, but a new influx of students--fueled by the GI Bill and postwar baby boom--necessitated additional expansion. Between 1959 and 1970 the College built several dormitories, a dining facility, faculty offices, a library, theater, and psychology lab, student union, science building, and parking lots. Even more construction, accommodating the “echo-boomers,” occurred between 1970 and 2003. Attractive but thirsty landscaping filled adjoining areas, eliminating natural habitat of native flora and fauna and increasing the institution’s consumption of water. Dependence on fossil fuels, another finite resource, also increased. Lake La Salle, 1943

As the College expanded, Lake La Salle became a flourishing habitat and refuge for wildlife and native fauna. Initially created to provide irrigation water for landscaping, the lake gradually filled with silt. Several attempts, made between 1941 and 1961, to remove sediment failed and the lake reverted to riparian woodland. Today, among a canopy of native red willows (and some introduced weeping willows), migratory waterfowl, warblers, vireos, owls, hawks, golden eagles, deer, fox, bobcat, coyote, and mountain lions find food and shelter, and students study stream ecology and geology, water chemistry, and plant and animal communities. Environmental Science/Studies faculty currently use the area as a living laboratory. Elsewhere on campus, efforts to enhance sustainability are well underway. They include a sustainability website, a carpool/rideshare program, energy conservation measures, recycling and food waste composting programs, an organic garden, a native plant garden, academic majors in environmental studies and sciences, and on-going student projects that investigate campus resource consumption and propose environmentally friendly alternatives. For example, Gretchen Lemke-Santangelo’s California history class is currently developing a sustainability plan for the College.    

As Saint Mary’s expanded, Moraga grew as well. Following Irvine’s death in 1947, his heirs sold the land to the Utah Construction and Mining Company, which in turn developed the property and sold parcels to other builders. Joining a Bay Area-wide trend of postwar white and capital flight out of inner-cities and into suburbs, developers began the process of converting orchards and fields into an affluent community distinguished by neat, uniform ranch-style homes, good schools, well-groomed parks, a golf course, country club, and a tastefully-designed shopping center. To its credit, the Town of Moraga (incorporated in 1974) has attempted to achieve a balance between development and preservation of open space through citizen involvement in town planning and insistence on controlled growth. Indeed, its decision to incorporate was partly a response to unchecked, unplanned suburban expansion initiated by developers during earlier decades. Perhaps one day Saint Mary’s sustainability initiative will extend to its nearest neighbor, and town and gown can move together toward a future grounded in the Saclan wise-use ethic and contemporary knowledge of ecological systems and appropriate technologies.



Hilson, Robert. “Restoration of Lake La Salle: An Environmental Analysis.” Senior Thesis, University of California, Santa Barbara, 1984.

Kimball, Sandy, Moraga’s Pride. Moraga, CA: Moraga Historical Society, 1987.

McDevitt, Brother Matthew. The History of St. Mary’s College, 1863-1963. Typewritten Manuscript, 1963, Saint Mary’s College Library Archives.

Chapel and Hills