Interactive Cartography of Spanish and Mexican California
Maps of the expeditions, engagements, and imperial contests of California between 1769 and 1848, reconstructed point-by-point from the archival record; above all the Archives of California (BANC MSS C–A), the Savage transcript copies that are the sole surviving record of the province's government archive after 1906. Every pin carries its source; uncertain locations are drawn so you can see the uncertainty.
Native California
Approximate homelands of the Native nations of Alta California at contact, labeled without invented boundary lines and grouped by language family. Companion to the Native Peoples Index.
Military Engagements, 1769–1848
Every documented engagement from the project's military register; treating Indigenous combatants as military actors, with campaign layers, a timeline, and register-keyed citations.
Coastal Defense of San Francisco Bay, 1776–1974
Every coastal-defense battery of the bay across six eras; from the Spanish Castillo de San Joaquín to the Cold War Nike missiles; one toggleable layer per period, each pin sourced to Bancroft and the NPS historic record.
The Presidial System, 1769–1846
The garrisons and artillery of the four presidios from the muster rolls and ordnance inventories, fort by fort and year by year, with Fort Ross as the benchmark one Russian outpost set for the whole coast.
The Bodega–Ross Corridor, 1775–1841
Sixty-six years on one stretch of coast: the 1775 survey, the failed 1793 occupation, the Russians at Ross, the Spanish probes that watched them, and the Coast Miwok who dealt with everyone. Companion to a research article in progress.
Ranchos of Mexican California, 1784–1846
The private land grants shown as territories, colored by the governor who made each one, from Borica to Pío Pico. About 400 ranchos carry their surveyed boundary; each links, where matched, to its hand-drawn diseño and archival record. The boundary companion to the Diseños gallery.
Population of the Californias, 1777–1847
Every count in the archive, settlement by settlement, in the documents' own categories. The headline: in 1790 the entire Spanish population of Alta California was 910 people.
Missionization — the Establishment System
Every fixed establishment of colonial California in pictorial symbols: the mission chain and its sub-stations, the parish chapels, pueblos, presidios and batteries, the Russian fort, port, and farms, and New Helvetia — founding orders from the archive on the popups.
Lighthouses of California, 1854–1939
Every light station, fog-signal station, and lightship station on the coast and inside San Francisco Bay, from the first federal cohort of 1854 to the last towers built before the war. The primary layer is the Light-House Board itself: 163 passages quoted from its annual reports, cited to report year and page.
Lumber Ports of the California Coast, c.1850–1940
Every documented lumber shipping point from chute-only dogholes to the deepwater mills of Humboldt Bay; the NRHP doghole-port inventory mapped with tonnage classes, loading technology, companies, cargo streams, the logging railroads that reached tidewater, and the lighthouses this deadly trade built. The last survivor of the sailing fleet, the schooner C.A. Thayer, threads through it.
The Secularization of the Missions, 1826–1846
How the mission system was dismantled: the decrees and reglamentos, every mission's documented handover, inventory, and 1845–46 disposition, the Híjar-Padrés colony crisis, and what the Indians said, in the record's own words; keyed to the Savage transcripts throughout.
The Bay Area Imperial Frontier, 1775–1841
San Francisco Bay as a contested borderland: Spanish defense and decay, Russian hunting and settlement, British and American probing; and the Native peoples who navigated all of them.
Gabriel Moraga's Expeditions, 1806–1817
A decade of interior and northern reconnaissance on one map; the 1806–07 valley probes, the 1810 Suisun and Bodega operations, and the Ross missions of 1812–13.
The 1806 Interior Expeditions
Zalvidea and Moraga's 1806 probes into the Central Valley, camp by camp from the Muñoz and Zalvidea diaries, with the Native villages they passed through as Cook identified them.
The Exhibit Series (new; under review)
Four new maps after the exhibit panels at Mission San Francisco de Asís: one shared canvas, the pre-1850 shoreline underneath, pictorial symbols, and the archive's anchors on every popup. The older maps below are unchanged while the two series are compared.
San Francisco Bay Expeditions
Five sea approaches as coastal ribbons, Ayala's longboat surveys, and the seven land expeditions of 1769–1776, with diary citations and C-A record anchors on the routes.
Ranchos by Era
The rancho portal's own boundaries overlaid by era or by granting governor; every parcel keeps its portal record, land case, and diseño links.
Languages & Native California
The Native California layers over the pre-1850 shoreline.
About & Method
These maps accompany a research project on Spanish- and Mexican-era California. They exist to make the geography of the archival record legible: where expeditions actually went, which Indigenous communities they passed through, and how competing empires pressed on the province.
Method. Routes are reconstructed stop-by-stop from expedition diaries and S. F. Cook's route studies; engagements are plotted from a maintained register compiled out of the C–A transcripts, Bancroft, and printed primary collections, and each map pin is verified against that register before plotting. Coordinates are best-available reconstructions, not surveyed points: solid markers sit at known places, translucent dashed markers are approximate within their district, and hollow markers are conjectural. Dashed route lines mean the party passed roughly this way. A small number of register entries (documents without a plottable location) appear only in the register, not on the map.
Native California. Most of the violence documented here was carried out against, and often alongside, Native Californians; as combatants, auxiliaries, intelligence sources, and polities defending territory. The maps use the sources' own terms inside quotation marks and name Native nations, villages, and leaders wherever the documents allow. "Punitive expedition" and similar phrases are the sources' framing, not an endorsement.
AI assistance. This site is built and maintained with substantial AI assistance (Anthropic's Claude), under the author's direction: the register compilation, verification passes, data files, and site code are AI-drafted and human-reviewed. Errors are mine; corrections are welcome and logged.
Companion project. The same research maintains Archives of California: A Documentary Calendar of the Savage Transcripts (DOI 10.5281/zenodo.21327098); map pins with a catalog record deep-link straight to it, and from there to the manuscript leaf.
Sources
The maps draw on roughly sixty distinct bodies of source material. What follows is the short form; the full source apparatus lists every one of them and says which map uses which, and each pin carries its own citation.
Archival & manuscript sources. Archives of California (BANC MSS C–A), Bancroft Library · U.S. District Court land case files, Bancroft Library · Online Archive of California and Calisphere · Vallejo, Documentos para la Historia de California (C–B) · Land Case Maps (diseños), Bancroft Library · Local historical societies and house museums · Presidio garrison and artillery register (unpublished) · and 2 more.
Printed primary sources. Bancroft, History of California, 7 vols. (1884–90) · Gibson & Istomin, Russian California, 1806–1860 · Russian-American Company material (AVPRI, Golovnin, Khlebnikov) · Period newspapers (Alta California, Mendocino Beacon, and others) · Davidson, Coast Pilot (1869; 4th ed. 1889) · USC&GS T-sheets and harbour charts · The Muñoz and Zalvidea diaries (1806) · and 11 more.
Datasets, boundaries & geographic data. NAHC / CNRA California Land Grants (PLSS) · ECAI / UCSD Spanish & Mexican Land Grants · USGS GNIS · USGS National Hydrography Dataset · Handbook of North American Indians, vol. 8 (1978) · OpenStreetMap · David Rumsey Map Collection.
Secondary scholarship & reference works. Cook, Colonial Expeditions (1960) · The redwood-coast literature (McNairn, Jackson, Carranco and others) · Thompson, NPS historic resource studies on the Golden Gate forts · Langelier & Rosen, El Presidio de San Francisco (1992) · Kroeber, Handbook of the Indians of California (1925) · Gifford & Schenck, Southern San Joaquin Valley (1926) · Milliken (2009) · and 6 more.
Government agencies, registers & digital repositories. Internet Archive and HathiTrust · California State Parks and the Office of Historic Preservation · National Park Service · Library of Congress · National Register nominations (NPGallery) · U.S. Coast Guard Historian's Office · Internet Archive Wayback Machine · and 1 more.
Tertiary web sources. Wikipedia and general-interest local-history pages · LighthouseFriends.com · FortWiki and NorthAmericanForts.com · California State Military Museum · Ed Thelen's Nike missile site database · Railroad-history sites.
Sources & Method → · per-map apparatus for Lumber Ports and Lighthouses.
Data & Reuse
Each map is driven by an open JSON dataset in
the repository's
data/ directory (schema documented there). Content is licensed
CC-BY-4.0, code MIT. To cite a
specific feature, use its permalink (the 🔗 link in any popup); to cite a map, use the
"Cite this map" button on the map page. No build step, no tracking.