Though buses between towns are frequent and inexpensive, by far the easiest way to travel Sonora is by car—towns such as San Carlos and Bahía Kino are very spread out, and some lack taxi service.
Flying is another option—Hermosillo, Guaymas, and Ciudad Obregón all have international airports offering regular flights from the United States—but Sonora's proximity to Arizona means that most visitors, even those in tour groups, enter in private vehicles or buses.