Nathaniel Northwest is a posthumous antagonist from the Disney animated television series Gravity Falls. He was one of the first mayors of the town, and was a corrupt and vile individual who used conspiracy and cover-ups to keep his position.
After Gravity Falls' founder, President Quentin Trembley, was impeached, the local government secretly made Northwest the mayor and supposed founder of the town. The Northwest Cover-Up, as it was called, gained Northwest considerable wealth and status in the community, which he immediately let go to his head. He convinced the workers of the town, including Archibald Corduroy, to deforest a section of Gravity Falls for the construction of Northwest Manor, in return for allowing them to partake in the manor's festivities when the construction was complete. Though many lives were lost in the extreme conditions during the construction, the manor was finished, but Northwest did not allow any commonfolk inside. Even when a flood hit that began washing away the waiting workers, Northwest looked down on them and mocked them as they drowned, leading Corduroy to use his dying breath to curse the Northwests.
Northwest continued his eccentric lifestyle of embezzlement, conspiracy, and destruction, until one day he tried to prove himself a wizard by eating a whole oak tree. He choked and died, though those who knew him did not mourn his passing. However, due to the Northwest Cover-Up, Nathaniel Northwest was immortalized in the town's history, with statues and paintings of him adorning the town.
After his passing, the Northwests would remain influential people in the community, with Preston Northwest becoming one of the wealthiest men in the town.
In the season one episode "Irrational Treasure", Dipper and Mabel discover the secrets behind the Northwest Cover-Up, eventually finding the government documents detailing the conspiracy. They give them to rival and descendant of Nathaniel Pacifica Northwest, which upsets her.
In the season two episode "Northwest Mansion Mystery", Archibald Corduroy makes good on his curse by returning to the manor as a ghost 150 years after his death, revealing the injustice the Northwest family showed him and his colleges. He plans to exact his revenge by turning everyone in the manor into trees if they do not open the manor to the populace, and while Preston refuses, Pacifica opens the doors and lifts the curse, righting the wrongs of her ancestor.