Board Thread:General Discussion/@comment-27745396-20160219205052/@comment-25246375-20160910162907

Stanley most likely only printed the machinery pages from the Universe Portal. But in the purchasable version of Journal 3 it says that after Bill was defeated, the town came back together and so did the journals. Burnt pages were also recovered, leaving some info like drawings from McGucket and Ford. (Spoilers?) Journal 3 was then thrown in the Bottomless Pit so that it could end up anywhere for someone to find it. Dipper also started his own Journal with a Pine Tree symbol.

Dunno if this counts as canon.