Grassrivers is Leonida’s version of the Everglades — mangrove-covered wetlands, slow rivers, and hidden waterways that Rockstar itself has called “the untamable jewel of Leonida’s crown.” It’s the wildest, least tamed region on the map, home to alligators, dense swamp vegetation, and — per Rockstar’s own warning — far deadlier predators and weirder discoveries than the gators alone.
Airboats are the main way to actually get through the marshes, and the region is reportedly tied to an in-world wildlife organization called POACH, hinting that Grassrivers may come with its own strand of side content built around hunting, conservation, or both.
It sits between Vice City and the more remote reaches of the state, giving players a very different pace the moment they cross into it.