Gershon, I got a pair of Sicilian Donkeys, commonly called "Miniature Donkeys". They are 36" or under at the shoulder and weigh up 350 lbs in good shape. Smaller ones are more expensive, and anything over 36" doesn't make the cut to qualify as a "mini" so bigger ones can be purchased for quite a bit less. Mine are at the big end of their size.

The reason I chose minis is because I wanted them to bushwhack with me, and I figured the shorter minis would do better in the undergrowth here.

They are pretty amazing bushwhackers too. They'll go just about anywhere I can and they'll always pick the route with the least resistance. If they knew where we were going I'd almost always be better off following them than leading.

Though the minis can pull a cart just fine, and a pair of them can be hitched together as a team, on the trip being described here I'd use a standard burro, and maybe two. They're herding animals and do better in pairs than alone, and we're talking a long trip here.

Burros are really better suited for these kinds of trips than a horse. They're a lot less picky about their diet, don't need to be shoed, and have a much calmer demeanor than horses.

Unlike horses, who think all food should be free and available and therefore don't respond to treats, burros will learn fast to do a double summersault backwards if they know there's an edible reward for their efforts.

Every evening Lewis & Clark bray at me to come give them their sweet grain. If I drive around to the bottom of the fenced in pasture they're in and yell for them they'll come running to find me. I play "hide and seek" with them like this. The point here is that they're not likely to wander off far, generally no further than the next bit of good forage, and if they think they'll get some kind of tasty treat when you call them they'll come running to you every time.

I have no idea about the laws for this type of trip in Mexico. When I've been there I've seen a lot of people walking along the roads, and some of them were a long way from any town. Quite a few times I've seen people come out of the fields/forest where they must of been camping and start walking on down the highway. But I've only been in Yucatan, I don't know much at all about the western states. The people and the police I met there were all good to me. That's not to say they won't take advantage of a gringo, but most won't, and the others won't if they know you're on to them.

The best advice I can give for a trip like this is be humble. Apologize for not knowing the language if you don't, and try hard to learn how speak to them in their language, don't expect or even ask them to speak ours. Everyone down there knows about us jabbing them with "Learn to speak english" when they're up here. Generally speaking we're pretty obnoxious about that and they'll have fun returning that given a chance.

When I've been there I carried the pocket book "Spanish For Dummies" with me. I take it out and show it to whomever I'm trying to speak with and say "espanol for loco gringos", and then point to words and try to say them. That's never failed to break the ice. That totally got me out of a traffic ticket in Merida, the officers just busted up laughing and told me to be careful and move on.