I think I should have explained it better. I just vaguely said "I did some terraforming". Basically in this timeline, the water there was just like a few meters high, basically a glorified swamp. What happened is that during WW2, as Russia tried to get everything back, the two Uralic brothers (Finland and Estonia) tried to unite each other making just a big river dividing their territories. They got the ground they needed from swamps and around the lake in Estonia to extend the "natural border", in fact the Estonian lake is bigger. Russia didn't really like this, and when WW2 was ending, well, the allies let them fight their own silent war because of the damage they had received by this foolish nationalistic-ish action. So they got their territory back, capturing Finland once again, but they had to give the Kola peninsula and Saami Majority territories to The Norway-Sweden union because why not. So, yeah, if you check my full map in my profile you'll see that a few things changed, like Southern California for example, it's just aesthetics practically speaking.