Is this a new game, or an old save?
If this is an old conservation, then the resource will appear when you open new territories, instead of black squares. The chance of occurrence is this: Report from 1 to 75, randomly, and when hit the number 50, a resource appears, of course, these numbers do not say anything, but this is a decent chance.
Also, in the last update, when creating a new game, a resource appears on the start zone.
White squares in the picture is the resource, this is the beginning of the game with the RSO mod
So you have an old preservation in this case, just scout the new territory.
I need to figure out how to do it better than now. For compatibility with old saves, so that you do not have to look very far for a resource.