Arizona and Sonora share the same ecosystem, the Sonoran Desert region. They share common history, several Native American tribes on both sides of the border, and they have six border twin towns. The natural boundary is 361 miles long and it has never been a totally closed border. Arizona needed Sonora's miners and ranchers and they have been the biggest source of migrants to the USA.
Because of the constant flow of people across the border, the Arizona-Sonora region <em>developed its own separate identity.</em> Many people living there are bilingual and commute daily to the other side of the border for work. Their value system has been affected by the proximity of a different culture. As a result of that, intercultural and interracial mixing took place that created a generation of people who feel a connection to both countries at the same time. Prejudices have been reduced and stereotypes abolished.
<em>The interdependence</em> between the USA and Mexico has always been and still is business related. Starting with vegetables trading, the cross border shopping and manufacturing developed into big industry today. A major economy connection has developed through the maquiladora sector. Arizona based companies operate about 30% of maquiladoras in Sonora and Sonora's economy is dependent on this and the automobile industry in Arizona.
Cross-border shopping, tourism ( for pleasure and medical reasons), joined environmental projects, bilingual schools and cultural events are all parts of the interdependence between the two countries.