Contents: Summary | Tools | Sources | Steps

Bee Lehman, last updated August 2026

There is an ArcGIS embed that should appear here. It might take several seconds to load.

This is an interactive map. Try clicking into the map and checking out the different pop ups. The map will work better viewed in ArcGIS Online.

Now, how did we do this?

Summary

The assignment here is to add historical data to a contemporary map. The intention is to highlight how that historical information contrasts against our contemporary boundaries in order to better understand our position against the events of the past.

Here, I’m looking at how to think about the historical locations of the Indigenous communities in what is now California against the invading Spanish missionaries and soldiers in order to better see which tribes the Spanish were attempting to colonize.

This project is about exploring 19th-century California history through maps. Over the course of the one century, the land changed hands four times (depending on method of count).

For the second map in the series, we took existent data regarding the historic lands of the Indigenous communities to compare against mission placement and Spanish expansion of colonial control.

Tools

For this project, I used the following, specific tools (i.e., machines and programs). Each are listed generally, noting what type of machine or program, before naming the specifics used in this sample.

Hardware

• Laptop computer, Dell with Windows

Software

• ArcGIS online (UC Berkeley community members can access through the GIS Libguide)
  • There is a freemium version. A license is expensive.
• Program for tabular data (here, Excel)

Sources

For this specific map, scholars and researchers had already spent significant time exploring various historical sources in order to better understand the past.

We first would like to extend our thanks to those scholars, acknowledging their monumental efforts.

The specific data sets and where to find them (as of 2026) include:

• “NAHC Digital Atlas,” State of California Native American Heritage Commission, accessed June 30, 2026, NAHC.
• “Maps of Private Land Grant Cases of California,” Calisphere, accessed June 30, 2026, Calisphere Collections.
• “Exploring the California Spanish and Mexican Land Grants - Overview,” ArcGIS Online, accessed June 30, 2026, ArcGIS.

Steps

This section provides a narrative description of the steps taken to complete the process. Each step includes a general statement of the goal and then provides a short description of how the project lead implemented the step.

Preparation Work

My first step was (as usual) to identify goals and outline possible methods to achieve them.

The project asked me to create a series of maps to provide readers with a sense of California history across the 19th century as control changed hands and borders were redrawn.

I grew up in Southern California and had a general sense of 19th-century coastal history, but focused on my home town. To better understand the political changes, I looked for reliable timelines from scholars laying out Californian history.

Among other material, I checked out:

• National Park Service (link to their GIS, Cartography & Mapping page)
• Two books

Choosing a rough 16 moments in 19th-century history, with the hopes to end with around ten visualizations. I picked more than I needed in order to have flexibility in coverage. I couldn’t expect to have access to every piece of historical information I wanted, particularly without extensive research time.

After selection, I took a look at first points: what kind of geopolitical control was the Spanish government trying to impose in the province of Alta California in the beginning of the century.

The form of colonization that the Spanish were imposing was centered around dense-population areas and concentrated in the lower portion of the state. To address that, I wanted 1. Spanish maps from the period. 2. I also needed information about indigenous community locations as they had practical control of the land through the first half of the 19th-century, particularly in the North.

That meant I wanted a combination of information about the historical boundaries of the Spanish province of Alta California as well as the spread of indigenous communities in the 19th-century.

Source Acquisition

Indigenous Communities

For indigenous data, I knew that US state governments often host information about the state’s heritage and history. I decided to start with a quick look and, going to Google, I searched for (california government native american map). In return, I got lucky and almost immediately found

</a>

• “NAHC Digital Atlas,” State of California Native American Heritage Commission, accessed June 30, 2026, https://nahc.ca.gov/cp/.

The data was exactly what I wanted.

I couldn’t download the information behind the map in the Native American Heritage Commission’s (NAHC) Digital Atlas. I knew, however, that most state governments try to provide their data to the public as open access material. I looked in Google for (NAHC data gis site:.gov) to find the organization’s (the NAHC) data on a government website (the “site:.gov”). Along with the (NAHC site:.gov), I added (data) and ( gis) to hopefully limit to datasets for a geospatial information system (GIS) like ArcGIS.

I found the perfect data:

• “Folder: NAHC (Native American Heritage Commission),” California State Government, accessed June 30, 2026, CNRA.

California Missions

Next, I need the latitude and longitudes of the Spanish Missions errected along the California coast. It would be easy to make that dataset, but I figured someone else likely made it available online.

To see if I could find it easily, I went to Google and looked for (california missions latitude longitude list).

Looking down the list, I found several options. I ended up going with

• “Missions: North to South,” California Mission Guide, accessed August 20, 2026.

The data was set up in the website as tabular data. I highlighted the chart, copied it, and pasted it into an Excel Sheet.

I then saved the data as a CSV (common seperated value) sheet both for

• stability and
• use in programs like ArcGIS Online

The Program

Publishing

Longevity

Indeterminate, expected three years minimum

This map is hosted in ArcGIS Online using an institutional, indvidual user account. That means if I leave the institution, it is likely that my account information and data will be flushed. As such, the assocaited data and map are depended on my relationship with the university. While I don’t currently plan to leave the university, life is mysterious!

As such, I like to plan ahead and make sure that I have downloaded, static stills of my map as jpgs foldered with my base data. That way I can recreate my map as needed and/or still have access to a version of the final product.