There have been several threads about starting north from Mexico on these routes. Attached is a file with GPS Tracks of several options. The one big attraction is the old school house at Lochiel and giant Fray Marcos monument. Kind of neat to say you started your trip at the exact same place the first Europeans entered the US in 1538. If you are on a good dirt bike, you can ride straight to Benson (92 Mi) bypassing Sonoita. The most scenic way is thru the National Forest N/W of Sonoita. If the desert has already heated by the time you start, I recommend going over Mt Lemon rather than up the San Pedro river.