Anyone who crosses the border from one country to the next requires a passport.
Zero. Mexico and California share a border.
Tecate, California is in the very south of California right along the USA Mexico border. In fact, directly across the border is the town of Tecate, Mexico.
You can step across since they share a common border,
California is in the United States, it borders only one other country. That is Mexico. More specifically: the State of Baja California Norte, Mexico. The states that share borders with California are Arizona, Nevada, and Oregon.
It is the capital of the northwestern Mexican state of Sinaloa. It is across the Gulf of California from the Baja California Peninsula. Its coordinates are (24.8°, -107.383333°)
The land across the Gulf of California is called Baja California, a peninsula connected to the rest of Mexico near the border with Southern California.
Mexico is the country south of the US states of California, Arizona, New Mexico, and Texas. Tijuana is just across the border from San Ysidro, California.
I guess you mean the Baja California Peninsula. It is one of the most visited regions in Mexico by American tourists. Some famous cities found there are Tijuana (right across the border to San Diego, California), Ensenada, Rosarito and Los Cabos.
Some of them include wheat, corn (maize) and rice. Western Mexico, specifically the state of Sinaloa (the mainland in front of Baja California across the Gulf of California) is considered the Mexican breadbasket.
Yuma is located in the extreme lower left corner of Arizona. Across the east border of California and above Mexico
The Sonoran Desert, one of the hottest and driest deserts in North America and shared with California and Mexico.
The Mexican cities across the border for the places you just asked are: El Paso, TX: Ciudad Juarez Laredo, TX: Nuevo Laredo San Francisco, California is some 765 kilometers (475 miles) away from the border. I guess you were meaning San Diego, California which is across the border to Tijuana.