Gravity Falls

History

Up to the point of the Transcendence, from which point the AU makes it's divergence from the cannon material, the history of Gravity Falls can be inferred to be fairly identical to that of the Gravity Falls from the official cartoon.

The source of Gravity Falls's weirdness stemmed from an alternate dimension, or the Mindscape, which was leaking into our world. Pre-transcendance, Bill Cipher used Gravity Falls as a testing ground of sorts. The merging of Gravity falls with the Mindscape would serve as the prelude to the Transcendence.

After the Transcendence, Gravity Falls would go down in history as being the origin of the event.

Post Transcendence

After the Transcendence took place, Gravity Falls became a much more notable town. Being the epicenter of the global change, researchers, cultists, and tourists began to flock to the small town. Despite all the attention it got, it never became anything more than a small Oregon town where interested people would find themselves headed.

It has special importance to Dipper in that the residents, despite his transformation, don't treat him differently from when he was human. For as long as that lasted, it played about as important a role as Mabel in keeping him grounded.