Is the book of gravity falls a diary?

Yes, the "Gravity Falls" book, often referred to as the "Journal," is a diary that contains notes, drawings, and observations about the supernatural phenomena in the town of Gravity Falls. It is primarily associated with the character Stanford Pines, who documented his experiences and discoveries while researching the mysterious events and creatures in the area. The journal plays a crucial role in the series, guiding the main characters, Dipper and Mabel, as they navigate the strange happenings in the town.