West of Nogales in southern Arizona, the Mariposa Land Port of Entry is one of the busiest land ports in the United States, serving as the entry point for millions of people and billions of dollars in trade between the US and Mexico each year. The original port, built in the 1970s, had become overwhelmed by the growth in traffic and could no longer support the evolving needs of a modern land port of entry. The new port is a study in balancing these needs with the experience of its occupants: necessary surveillance with compassionate interactions, operational efficiency with a healthy work environment, and economic opportunity with sustainable solutions.

Influenced by the smooth, continuous lines of a railroad yard and the contrasting vision of a desert oasis, the site design wraps the port’s utilitarian needs of vehicular and pedestrian processing around a lush central garden for port staff and visitors. Pedestrians are led towards the center of the site along a quiet shaded path to continue their passage north. U.S.-bound vehicular traffic splits at the southern edge of the site, sending private vehicles to the west and commercial vehicles to the east. The central spine of the port is the Oasis, a desert garden running the length of the site that provides respite from the harsh climate and the stress of border protection. Each path crosses the threshold of the new port marking the entry into the country: a canopy of color—red, white, and blue—stretching 1000 feet across the site. This organization, which treats visitors and staff with dignity and streamlined traffic on-site, is now regarded as the model for land port of entry design at the southern border by the GSA and Customs and Border Protection.

Materials like concrete, steel, and glass reflect the ruggedness of the desert terrain that connects the borderland. A pattern of footprints are cast in the exposed face of the insulated concrete walls, alluding to the journey that many migrants take across the border each day. Canopies, trellises, and roof structures are made from raw, mill finish steel, weathered with a layer of natural rust that protects the steel and patinas over time. Full-height glass connects the interiors with the gardens of the Oasis and round porthole windows are carefully placed to view the surrounding landscape, reminding the port staff of the connection to their natural environment.

Two art installations were commissioned by the GSA as part of their Art in Architecture program. At the southern entry, pedestrians pass under video portraits showing the daily reality of migrants commuting between both countries, exhibiting their journey and the shared culture of the people in the borderland. Leaving the pedestrian processing area, the inverted topography of the Baboquivari Mountain range hangs above those entering into the U.S., marked by a trail indicating the once treacherous passage of people across the landscape. These pieces speak to the connection between the sister cities of Nogales, the people moving across the border daily as an ethereal, transnational population, and to the two bordering countries.

The port is grounded by the concept of a nurturing garden sanctuary in the center of a harsh, arid terrain. The Sonoran Desert climate is characterized by the rare abundance of rainfall in the monsoon season set against the many months of scarcity. One million gallons of rainwater are harvested from the building roofs and site to sustain the plant life throughout the site, including the central Oasis. Passing through moments of generous shade and vibrant landscape, visitors are left with the lasting impression of a humane welcome to the United States.