Nathaniel Northwest

 is the supposed founder of Gravity Falls, Oregon. He is the great-great grandfather of Pacifica Northwest. His legacy is celebrated during Pioneer Day. A statue of him can be seen in "Irrational Treasure," when Dipper and Mabel are reading from Journal 3 on the steps.

History
It was revealed in "Irrational Treasure" that Nathaniel Northwest was not, in fact, the true founder of Gravity Falls. He was actually a "waste-shoveling village idiot," and the true founder of the town was the shamed and relatively unknown eighth-and-a-half president of the United States, Quentin Trembley.

As seen on a page in "The Northwest Cover-Up" he communicated in "a series of grunts and gestures." Following that passage, it is shown that his catchphrase was, "I am going to eat this entire oak tree because I am a powerful wizard!"

It also states that his last moments alive were spent choking on a giant piece of oak bark that he was trying to eat, wanting to prove his claims of being a wizard.

His statue makes a brief cameo when Bill Cipher mentions knowing "lots of things." Namely famous conspiracies.