From the little town of La Isabela, there are no rivers to ford. There is if you are in Luperon. But, as I posted, there is a new bridge at Ranchito...
But you said La Isabela.
Okay, if your are adventuresome you can take the road to Estero Hondo and continue straight. That road goes to El Papayo where you go to the left and up the hill. You come down in Cruce de Agua de Palma. There you would go to the right and take that road to Buen Hombre. From there I am not real sure but I think you need to go to the left and come out on the main highway, where you go right again.
Alternately, you can go from La Isabela south to El Mamey, up the mountain and down through the Paso de los Hidalgos, You come out on the Duarte Hwy at Cruce de Guayacanes and take a right. Follow your nose to Montecristi. Much easier drive.
When you get to El Mamey, you have to got to the right....if not, you end up in Guananico!! (I missed the turnoff one year and did that!!)
HB