From Tucson/Nogales, Arizona
From Magdalena, Sonora
From Lukeville, Arizona
After crossing the border from Lukeville into Sonoyta, continue on route 2 until you reach Caborca (it's about a 2-hour drive).This is a free trade zone, so no vehicle permit is required, but if you plan to stay in Mexico longer than three days you'll need a tourist form (commonly known as an FMT), which you can obtain at the 21km customs station.
From Hermosillo, Sonora
If you happen to be coming from Hermosillo or southern Sonora, just take route 15 north to Santa Ana, and take a left turn at route 2 (shortly after passing the topes (speed bumps) the road curves to the right - stay in the left lane and take your first left). Route 2 will take you directly to Caborca, after passing a toll booth and the pueblos of Altar and Pitiquito.
Green Angels Roadside Assistance - The state of Sonora provides a free-of-charge roadside assistance program known as the Green Angels. Easily identifiable from the green trucks they travel in, the bilingual Green Angels are prepared to assist you in resolving mechanical difficulties, providing radio communication or assisting with directions. They have a hotline number - 078 - that can be dialed from any cell phone or public phone in Sonora.
There is also an emergency number in Sonora that you can dial from your cell phone or a public phone (similar to 911 in the U.S.) - 066.