Mariposa (; Spanish for "Butterfly") is an unincorporated community and census-designated place (CDP) in and the county seat of Mariposa County, California, United States. The population was 1,526 at the 2020 census. Named for the monarch butterflies that overwinter there, the community's history is deeply intertwined with the California Gold Rush of the 19th century.
During the California Gold Rush, prospectors flocked to Mariposa for its rich mineral resources in streams and underground veins. Among them was John C. Frémont, Mariposa's most prominent resident, who leveraged his extensive mineral claims to achieve national prominence. He became the first U.S. senator from California and the inaugural Republican presidential candidate, significantly impacting both Mariposa and American politics during the 19th century's period of expansion.
Today, Mariposa preserves its rich heritage through numerous museums and landmarks that highlight its mining history. The county's proximity to Yosemite National Park also significantly contributes to its economy, with tourism playing a central role in supporting local businesses.
Geography.
Mariposa is nestled at an elevation of in the rugged foothills of the Sierra Nevada. According to the United States Census Bureau, the CDP covers a total area of , with nearly all of it being land. The community is situated in the valley of Mariposa Creek, which flows south then southwest into the San Joaquin Valley.
Major highways intersect in Mariposa; California State Route 49 and California State Route 140 merge for through the town's main street. Route 49 extends southeast to Oakhurst and northwest to Coulterville, while Route 140 leads southwest to Merced in the San Joaquin Valley and northeast to Yosemite Valley.
The area's soil predominantly consists of brown to reddish brown loam of the Blasingame series, and a gravelly loam known as the Boomer series. These soils support a thick grassland and diverse trees such as blue oak, black oak, gray pine, and ponderosa pine. To the west-northwest of the town, sparse vegetation and rockland are underlain by serpentine soil of the Henneke series.
Climate.
According to the Köppen climate classification system, Mariposa has a hot-summer Mediterranean climate (abbreviated "Csa" on climate maps) and wet winters.
History.
Early Inhabitants and Spanish Naming.
Before Spanish arrival, the Southern Sierra Miwok lived in what is now Mariposa. In 1806, a Spanish priest traveling with early California explorer Gabriel Moraga named the area. When the expedition came upon a creek filled with thousands of yellow butterflies, they called it “Las Mariposas,” the Spanish word for butterflies.
Rancho Las Mariposas.
In 1847, John C. Frémont purchased a 70-square-mile land parcel known as Las Mariposas for $3,000. Formerly owned by Governor Juan Bautista Alvarado, the ranch turned profitable once Frémont discovered a five-mile quartz vein producing hundreds of pounds of placer gold monthly. Its “floating grant” status, however, sparked extensive property and mineral-rights disputes. Squatters and mining companies contested ownership until 1856, when the U.S. Supreme Court ruled in Frémont’s favor. The Mariposa Estate covered 44,000 acres in the heart of the Mother Lode region, where gold pockets in quartz veins could yield between $100 and $30,000. By 1915, total output surpassed $12 million in gold.
Founding of Mariposa.
Mariposa’s rise as a gold rush boom town began along a seasonal trickle called Agua Fría, where prospectors—lured by tales of glimmering placer gold—pitched their first camp. When floods and fires during the winter of 1849–1850 forced them to higher ground, they relocated near Mariposa Creek, establishing a bustling county seat by 1851. The historic courthouse, completed in 1854, still stands.
Mariposa War.
During the early 1850s, tensions between local Native tribes—primarily the Southern Sierra Miwok—and white settlers peaked, prompting the Mariposa War. The conflict stemmed largely from the presence of miners and the trading operations of James Savage along the Merced River and Mariposa Creek. Alarmed by escalating violence, Mariposa residents formed volunteer militias. With state backing, these militias eventually secured control of the area. Modern historians also consider the Mariposa War part of the California Genocide, and it indirectly led to the so-called “discovery” and naming of Yosemite Valley. By the late 19th century, many Miwok people had been forced from their ancestral lands.
Twentieth Century and Beyond.
In 1914, voters in Mariposa County narrowly approved the creation of a county high school. Following a bond measure of $12,000 and the donation of nearly eight acres of land by the Mariposa Commercial and Mining Company, the school’s permanent campus opened in 1917. 
During World War II, the U.S. Army constructed the Mariposa Auxiliary Field (1942–1945) to train pilots; post-war, the site was redeveloped as today’s Mariposa-Yosemite Airport.
On July 18, 2017, the town was evacuated due to the rapidly spreading :Detwiler Fire, which threatened Mariposa and its surroundings.
Demographics.
2020.
In the 2020 census, the Mariposa Census County Division reported a total population of 12,981. About 31.6% of residents have at least a bachelor's degree. The community has a notably older demographic, with a median age of 55.6 years and 33.4% of the population aged 65 years or older. The area encompasses 5,489 households. The median household income stands at $64,490, while the employment rate is relatively low at 43.3%. Health care coverage is quite widespread, with only 4.7% of the population going without it.
In terms of racial demographics, Hispanic or Latino individuals constitute 1,568 residents, about 12% of the total population, which is significantly lower than the statewide average of nearly 40%. American Indians account for 434 residents, representing approximately 3.34% of the population. Veterans comprise 11.9% of the populace.
Economically, 12.6% of residents live below the poverty line. The percentage of government workers in the workforce is remarkably high at 35.7% compared to the statewide average. The homeownership rate is high at 76.4%.
Government and public safety.
Government representation.
In the California State Legislature, Mariposa is in the Senate District, represented by Democrat Angelique Ashby, and in the Assembly District, represented by Republican Joe Patterson. The County is administered by its elected five-member County Board of Supervisors.
Policing and public safety.
The county's policing agency is the Mariposa County Sheriff and staff. The Mariposa County Fire Department provides fire protection and emergency medical aid.
Attractions.
Mariposa Town Historic District.
The Mariposa Town Historic District, listed on the National Register of Historic Places in 1991, represents a significant part of California’s Gold Rush history.
The district includes sixty-three historic buildings, among the oldest in the state, reflecting the architectural styles of the era. Key landmarks within the district include the Mariposa County Courthouse, constructed in 1854, and St. Joseph’s Catholic Church, completed in 1863, known for its Carpenter Gothic design.
Mariposa Fairgrounds.
With a history dating back to 1939, the Mariposa Fairgrounds in Mariposa, California, are a central hub for community and cultural events. They host the Mariposa County Fair, known for its rodeo and demolition derby.
California State Mining and Mineral Museum.
The California State Mining and Mineral Museum, part of the state park system and located in Mariposa on the county fairgrounds, showcases California's mining history and mineral resources. The museum's collection, started in 1880 and originally managed by the first State Mineralogist Henry G. Hanks, includes over 13,000 items such as minerals, rocks, gems, and fossils, and highlights significant artifacts like the crystalline gold Fricot Nugget from the Gold Rush. It features interactive exhibits like a replica mine tunnel and a working stamp mill, illustrating the gold extraction process from quartz rock.
Mariposa Museum and History Center.
Founded in 1957, the Mariposa Museum &amp; History Center in Mariposa County features exhibits related to Native American culture, Spanish settlement, the Gold Rush, Yosemite, and Mariposa history. The museum also houses a significant archive, including photographs, special collections, and county records in its vault.
Notable residents.
Some living past and present notable residents in alphabetical order include:
References.
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