Fallout Cascadia is a new mod that allows the game to take place in Seattle. This means that the mod provides a completely different experience for the players.
The plan of the mod is to give the game a completely separate experience. You would not be able to create a character, see Fallout 4’s intro movie, or travel between locations.
The mod is set “several decades” after the events of the actual Fallout games, and will include Seattle and other locations “including Mercer Island, Redmond, Bellevue, forested areas and airports.”
Some of the people involved on this project have also worked on Skywind, the attempt to remake Morrowind using Skyrim’s engine. One of the developers said that this project will take a lot less time than Skywind, which had 70% of its stuff made from scratch.
Cascadia’s team are hoping to release the mod on PC, and they are hoping to get the mod on consoles.