On day 1 of Big Oil you can run out of the map, if you wan't to do this, do as said.

Load up big oil. Go to the van and head where there is trees and rocks (some rocks) and keep going, or you can follow the road (left of the van), there are some cutable fences.

Directions: << ^^ >> Head ^^ for the rocks, trees etc, << for the road.
VV