The San Luis River empties out into it. In Redemption, this location does not count toward 100% Completion. In Redemption II, the player can cross this body of water to get into Nuevo Paraíso by using a glitch on the Mexican side of the water's shore.
In both games, the Sea of Coronado is the westernmost point of the map, and is the tail-end of the San Luis River. It extends from Gaptooth Ridge into Punta Orgullo in Mexico, and serves as a physical boundary. It is more accurately a lake or an inlet rather than a sea.
Because Marston cannot swim, the sea cannot be crossed in Red Dead Redemption. However, in Red Dead Redemption 2, because horses are capable of swimming, the player can easily cross to the other side; the player can pass through two ravines and even briefly go past the border of New Austin and outside the marked game boundaries, but cannot get onto the ledge without exploiting a glitch. On rare occasions, a wolf might spawn.
The Sea of Coronado extends into Mexico and is bordered to the east by Punta Orgullo. The rebel stronghold of Nosalida is established along the sea. In Red Dead Redemption II, the Mexican side of the sea can only be accessed via glitch; interestingly enough, the player can follow the sea past Nuevo Paraíso and reach the south-end of the Sea of Coronado, which extends into an unnamed Mexican territory. A canyon surrounds this area, and fish will even spawn here, but the player cannot use their fishing rod.
It is possible that states/territories representing California and Baja California exist west of the Sea of Coronado, as Marston tells Sam Odessa in the Stranger side-mission California that California should be directly west of New Austin.
- The Rebels in Nosalida seem to be fleeing in the direction of the sea.
- The sea is possibly named after Spanish Conquistador Francisco De Coronado.
- It is loosely based on the real-life Sea of Cortez, which separates the Mexican states of Sonora and Baja California.
- However, unlike the real-life Sea of Cortez, the Sea of Coronado does not lead into the Pacific Ocean, but rather ends south of Nuevo Paraíso and is surrounded by an unnamed mountain range.
- The Sea of Coronado may also be based on the Colorado River, which separates both Arizona from California and Sonora from Baja California in real-life.