Above Cayuse referred to FS Rd 39, it runs west from the Nogales area to Arivaca, fairly close to the US/Mexico border. It is a spectacular and extremely remote area, within 80 miles of Tucson. Prior to the economic turn down, it was a prime passage for illegal immigration, but since then migrant activity is minimal. Along the road/corridor there are deep canyons and rugged mountains that run from the border to about 30 miles north. There are a couple of formal trails, one to near the top of Atatosca Peak where there was an old FS fire lookout, since burned over, and another in Sycamore Canyon that goes south from the road right to the border, about 7 miles. Prior to the fire, the lookout tower was open and campers could stay in it; years back Ed Abbey did work there one season. There is camping at the Sycamore Canyon access, and depending on the time of the year, you have to get your feet wet during the hike. The area used to be riddled with trails at the height of migration and hiking was easy, now those trails have been significantly overgrown, but hiking is still viable. I like hiking in the canyons because as long as you stay in one canyon, getting lost isn't to big a problem. Looking at a map it is fairly easy to create loops from one and back another. And remember, while the official line is migrants are dangerous, most often they want to see you less than you want to see them, and they make a point of avoiding you. Happy trails