Tucson y Hermosillo:

Shared History and Divergance in Two Desert Twins

Introduction: 1780 and the Imperial Borderlands

Imagine this with the year 1780. Why this year? No reason other than at this point in time the Spanish Empire had colonized basically what it was going to colonize in the Americas. The region of Nuevo España that is now Southern Arizona and Sonora and some surrounding areas was called the Pimería Alta  Pima being the name for the O’odham people who lived there prior to Spanish arrival and still do to this day. This article is called Hermosillo y Tucson because both of these cities existed as villages and were founded as we know them today during the period of the Pimería Alta.

The Rio Salado Project and Tucson’s Urban Revival

For those of you not interested in history, we will now get to the point and the modern implication. Over the past approximately 10 to 20 years there has been an initiative called the Rio Salado Project to “revitalize” downtown Tucson. For a long time, like in many American cities, downtown Tucson was basically just office buildings. The people around it were quite low income or unhoused. There was no economic opportunity for the people who actually lived in the region. The people who worked in the offices just commuted in from the suburbs or something like this.

Tucson, like other cities, is trying to change this and bring life and investment back into its core. But what is interesting is that underneath downtown Tucson there are the foundations of the Spanish presidio. Once, Tucson was a fortress town on the imperial frontier. Part of the efforts of the Rio Salado Project have been to bring what is called New Urbanism to Tucson, that is, creating more human-scale, walkable, livable neighborhoods and communities.

Tucson and Hermosillo: Shared Histories, Divergent Forms

Now we're going to get to the part about Hermosillo, Sonora. Because like Tucson, not many people actually lived in Hermosillo back in 1780. Tucson only had a population of around 1,000 and maybe more during the peaks of the war that was going on at this time. But now both Tucson and Hermosillo have populations of about a million. They are both situated in the Sonoran Desert, so they have similar climates and deal with similar issues, such as heat and sandstorms.

But a key difference in how Hermosillo and Tucson have developed is that Hermosillo, like most cities in Mexico, is much denser than most American cities. Well, by the standards of many central Mexican cities such as Mexico City and Puebla, the only two I’ve personally visited, the population of Hermosillo is not that dense. But the same can be said when one compares Tucson to the American Northeast. The oldest cities in Mexico are in the central mountainous region, and the oldest cities in the United States are on our northeastern coast.

Repairing Past Damage: Urban Policy and Preservation

The Rio Salado Project is also making a deliberate effort to try to address some historical grievances. In the 1950s and 60s, like many American cities, a highway was plowed through the middle to get close to downtown. A lot of older buildings were demolished to be replaced with what were then considered higher-quality, modern buildings like skyscrapers. So much of what is now downtown Tucson doesn’t only sit on the site of the old Spanish fort — it sits on the foundations of the actual old city of Tucson.

Some of the old city survives to the south and north — for example, the Armory Park neighborhood or Barrio Viejo. And the Rio Salado Project has decided that while we cannot bring back what has been destroyed, we can restore some of the experience, some of the architectural legacy, and some of the cultural implications that brings with it — through the construction of new neighborhoods that are built in a style more reminiscent of a Sonoran style.

Townhomes and Sonoran Architecture in the Desert Southwest

In the state of Sonora and much of Mexico, homes tend to be built closer together, think townhomes that form a solid face of buildings along the street. Imagine walking through a neighborhood in Chicago, New York, or Boston where it’s buildings two or three stories high and all their walls are touching, but they’re not apartment buildings, they’re multi-level homes.

Many of these are now being built more and more across the United States, but there’s a deliberate effort in downtown Tucson to build ones that reflect the Spanish and Mexican heritage of the city, including a large portion of its population.

Design and Experience: Built Form Shapes Human Life

Design shapes our experience of life and how we experience the world around us. The emotional and sensory experience that one has walking around Barrio Viejo or a new downtown development in Tucson built in one of these styles is different than what one experiences walking through a traditional American suburb, which has been the predominant development pattern for the last 80 to 100 years.

We can choose to design things that reach farther back into the past, models that have already existed in this place and encourage more human interaction, more physical activity through walking, and physically encourage more community building, because people just see one another more often.

Conversation from Hermosillo to Monterrey: Density in Dialogue

I once spoke with a man who had moved from Hermosillo to Tucson. I asked him how his experience was different living in Tucson as opposed to Hermosillo. Of course, he told me there were things he liked about living in Tucson — for example, he felt more physically safe in terms of crime rates. There was a lot more access to nature and trails; he was a big hiker. But he missed the opportunities for social interaction that one has living in a place like Hermosillo — more life on the streets and things like this.

However, I’ve also spoken with persons from Monterrey, Nuevo León. When I mentioned how unwalkable Phoenix was, they said they understood — because Monterrey was also built in a car-dependent way. However, when one looks at Monterrey in comparison to most American cities of that size, it is leaps and bounds ahead. It’s denser. It has a rapidly expanding light rail network. And those two things alone make it much more navigable without a car than most American cities.

Health, Shade, and Human Scale

In essence, Tucson is trying to become a better, healthier place for its residents to live. Another upside to denser development is that it increases the amount of shade over streets,  from the planting of trees that are closer together and taller buildings. This decreases the amount of energy that individual buildings have to use to cool themselves, because they shade one another as well as pedestrians.

Anyone from a desert will tell you, 90 degrees in the shade in the desert isn’t too bad. It can feel dramatically cooler. That is another subjective human experience that we should actually treat as a data point, because we are creating spaces for people.

From Brasilia to Tucson: Lessons in Urban Form

The famous example of not creating a city for people is the capital of Brazil, Brasília, which was built using all the best design methodologies of the time. They say it looks right from the plan, but to live there at ground level? It’s not quite so nice. Everything is very far apart. Commute times between one place and another can be long, even though there’s actually nothing in between.

In Tucson, we have the problem that the only thing between A and B is an endless field of single-family homes, whose residents you won’t be running into. If you biked or took public transit from A to B, you might run into those residents. You might run into someone you know. These kinds of small interactions are very important for our mental health, and, as it turns out, our physical health too.

These kinds of small interactions are very important for our mental health and our physical health too. One study found that social connection factors are independent predictors of mental and physical health and even mortality. Another showed lack of social connection is a greater detriment to health than obesity or high blood pressure. 

Resource Consumption and the Case for Density

And at the end of the day, for those who like pure numbers and tables, it’s a matter of resource consumption.

Less healthy people put more strain on health systems. Buildings that are farther apart and unshaded create a heat island effect and require more energy for cooling. More vehicles are needed. More roads are needed. And someone has to build and maintain all of it.

When things are closer together, much less energy is expended, for climate control, for transportation, for everything. It’s also important for comfort. The human eye is only comfortable perceiving about 100 meters in width. That’s why walking down the street in Paris or New York feels normal, and why walking down a Phoenix stroad feels like walking on the side of the interstate.

Conclusion: Build for People, Not Plans

To me, the logical conclusion is to build denser, less resource-intensive cities that are healthier for residents, mentally and physically, and that are more comfortable and enjoyable to live in.

APA Reference List

Bureau of Transportation Statistics. (2022). Border crossing/entry data: U.S. Department of Transportation. https://www.bts.gov/browse-statistical-products-and-data/border-crossing-data

Instituto Nacional de Estadística y Geografía (INEGI). (2020). Censo de Población y Vivienda 2020. https://www.inegi.org.mx/programas/ccpv/2020/

Metroplan Hermosillo. (2019). Plan de Desarrollo Urbano Sustentable de Hermosillo 2019–2030. Gobierno Municipal de Hermosillo. https://hermosillo.gob.mx/plan-urbano

Pima Association of Governments. (2022). Regional Mobility and Accessibility Plan 2045. https://www.pagregion.com/transportation/transportation-planning/long-range-transportation-plan/

Smith, A., & Jones, L. (2021). Cross-border commuting and urban development: A case study of Nogales and Hermosillo. Journal of Borderlands Studies, 36(4), 601–620. https://doi.org/10.1080/08865655.2021.1877312

U.S. Census Bureau. (2020). American Community Survey 5-Year Estimates. https://data.census.gov/

Valenzuela, J. (2023). El proyecto Río Sonora y su papel en el desarrollo sustentable de Hermosillo. Universidad de Sonora. https://riunison.mx/handle/123456789/899

Copyright © 2025 Ryan Badertscher. All rights reserved.