Nathaniel Northwest

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

It is soon revealed that Nathaniel Northwest is not, in fact, the true founder of Gravity Falls. He was actually a "waste-shoveling village idiot" and that the founder was instead the shamed and lesser known eighth-and-a-half president, 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!"

Also on that page it states that his last moments alive were spent choking on a giant piece of oak bark that he was trying eat, wanting to prove he was a wizard.