Preston Northwest

"Oh, and whatever happens, just remember one thing: you're a Northwest. Don't lose."

- Preston to his daughter

Preston Northwest is the Patriarch of the prominent Northwest Family of Gravity Falls, Oregon. A rich and influential man, he is the descendant of the towns' supposed founder Nathanial Northwest (later revealed by Dipper and Mabel Pines to have been a lucky idiot who was handed the credit as part of a Government conspiracy to hide the true founder) and the father of Pacifica Northwest.

In most of his appearances, Preston is relegated to the background and is characterized as simply a selfish rich man. However, Preston later proved to be one of the most callous, unpleasant, and outright evil people that Dipper ever faced, in some ways worse than many of the actual supernatural threats he had to battle.

History
Preston is introduced in "Irrational Treasure" celebrating Pioneer day with his family and using his relation to the Town's supposed founder as an excuse to lord his superiority over the people.

He later returns in "The Golf War" to drop his daughter off at a match between her and Mabel, however rather than stay to support his daughter, he and his wife leave to go to a party– offering her the words of advice: "Don't lose".

But its not until "Northwest Mansion Mystery" that Preston demonstrates just how evil a man he truly is, in fact serving as the true main antagonist of the episode. Preston's ancestor Nathanial had manipulated local lumberjacks into building what became the family mansion 150 years earlier, by promising he would use the space for a great public service– an annual party held by the family for the workers in the community. However, on the day of their party, the Northwests refused to let in the Lumberjacks and hold up his end of the bargain– instead laughing them off and enjoing a soireé for the rich. Adding injury to insult, the mass removal of the mountainside trees caused mudslides that same evening which killed several of the lumberjacks. One lumberjack among those who died swore a curse on the Northwest line with his dying breath; unless they agreed to honor the promise and let the common folk into their annual party after 150 years he would return to seek revenge.

As the curse began to come true, rather than opening the gates and letting the common folk in to break the curse, Preston instead forced his daughter to manipulate Dipper into getting rid of the ghost. Its revealed in this episode as opposed to simply being neglectful, Preston is outright emotionally and psychologically abusive towards Pacifica– going so far as to train her to respond on command to a small bell he keeps on his person (like a dog).

After Dipper succeessfully trapped the ghost in a silver mirror, Preston thanked him and then began to welcome his guests. However upon learning the truth from the trapped ghost, Dipper angrily stormed back in and called Preston out for his callousness and deception. While Pacifica attempted to apologize to Dipper, Preston intimidated his daughter into silence before smugly dismissing Dipper and his anger– reminding him that this would be the last time anyone of "his kind" (the commonfolk) would be allowed at his party.

However, the ghost managed to free itself from the mirror and began terrorizing the party, transforming the guests into wooden statues and causing general mayhem. Rather than agree to break the curse and save his guests, Preston instead hid with his wife and a butler in a panic room– leaving everyone else to their doom.

Once the ghost had turned everyone into wood, it planned to burn the mansion down killing everyone. However, Pacifica (having received renewed confidence from Dipper) decided to go against her family's legacy by breaking the curse. However Preston was watching the scene from a trap door, and emerged to order his daughter to leave the gates closed and join them in the panic room (he also reveals his plan to kill and eat the family butler if their food ran out before the ghost left). However finally standing up to her psychologically abusive father Pacifica opened the gates, letting the common people in and breaking the curse. This undid the ghost's damage and saved everyone. However, Preston's only response was narrowminded shock and terror that the common folk were invading his party.