Leading up to the release of Red Dead Redemption 2, it was leaked that the game map would possibly include the entirety of Red Dead Redemption's map. After Rockstar revealed the game's official locations, which aligned with those on the leaked map, we all took it as confirmation.
However, now that the game has been released, a different picture arises.
Since Red Dead Redemption 2 is barely out, many of you may be excused for thinking that none of the Red Dead Redemption map is in the game, that it was all a ruse. This isn't quite the case either. As review embargos were lifted, several publications including Forbes reported that a large western portion of the game world is locked off until you finish the story. As it turns out, this region is all of Red Dead Redemption's map sans Mexico with updated graphics.
You can unlock this western region by completing the main storyline. After the story is finished, you enter a free-roaming "epilogue" of sorts that gives players free rein to complete any activity left unfinished. It also allows you access to these easter-egg locations.
This area of the map is located to the southwest of the Lower Montana River, which runs westward from Flat Iron Lake, south of Blackwater. It contains every area present in Red Dead Redemption north of the San Luis River. Comparing the two, even with Mexico missing, you'll see how much bigger the game world of Red Dead Redemption 2 is than its predecessor's.
While it is a shame that the Mexican portion of the map wasn't carried over like the rest of it, this doesn't mean that it won't be added later on. It could be included in future DLC for either the singleplayer mode or for the upcoming Red Dead Online. That said, GTA 5's map has remained unchanged ever since release, so we wouldn't bet on it.
The "secret" western portion of the map can also be revealed using the cheat that clears the fog of war from your in-game map screen. You can check out our list of cheats right here.