Went on a tour there as well!!! It was in Nuevo Vallarta (20 mins from Puerto Vallarata)
We rod up a half dried up river beds, ( still lotsa water for splasing your buddies.
There were live cows in the river drinking the water, weren't fazed at all by the quads. Apparently they filmed Predator there...?
Rode through some ghettos, all the kids come running our to wave!
We only had five people in our group so we got to ride at a decent pace.
If I remember it was like 80 bucks, it was fun to get out there and explore a lil bit