if in the Jacumba area, you might meet citizen vigilantes - don't ask how I know
many years ago (in the late '90s), Michael and I were bouncing around there on dirt trails in the Blazer when we encounter a road block - get out of the truck to investigate, only to suddenly face people having walked up to the truck and us, in some sort of uniform, with gubs . . .
they advise we turn around, even though this is an official Forest Service road, and we showed them on the map: "don't matter to us what the map says, you cannot go through here" - oh kay . . .
needless to say, we have not had an urge to go back there, ever . . .
they weren't Forest Service, they were not Border Patrol, they had no identifying emblem on their trucks or uniforms, and they did not in any other way introduce or justify themselves, other than "you have to leave this area"