The Happy Trails Trailer Park is the trailer park where Chester McBadbat, his father and his friends live, inside a run-down mobile home.
The trailer park they are located in is ravaged by many tornadoes which strangely doesn't affect the rest of Dimmsdale. Next to the trailer park is a railroad, and across from the railroad is A.J.'s house. Chester and his father live inside a trailer within the trailer park, which is small. Chester's trailer also has a mailbox which is often shot like a rocket by people who do not like Chester's family name.
The trailer is tiny, with a single door leading inside. There is only a single room which is where the McBadbat's eat, sleep, and use the toilet. In almost all of his appearances, Bucky is sitting on a toilet right in the middle of the trailer, in many cases he is not even using it for anything except a seat (He notes in "The Big Scoop" that he will eventually need to get a chair in the trailer). In "It's a Wishful Life", it is shown that if Timmy was never born, the trailer would be a triple-wide with gold cinderblocks holding it up. The trailer remained this way until Timmy has Jorgen unwish the wish that removed his existence.
When Chester wished for his father to be the best baseball player ever, the trailer and the trailer park became a fancy mansion and a fancy yard. However since this was a wish by Norm, it eventually backfired, which lead to the mansion being taken away and Chester's father being arrested. When Norm came back as a fairy, Chester immediately wished for everything to be back to normal. This made the yard became a trailer park again as well as returned Chester's trailer to the park. Chester's father was returned to being a despised person again, but Chester was happy that his father was not in jail anymore.
The trailer was seen in the devastated future from Channel Chasers, still intact for twenty years, until the beginning of the movie when it was destroyed by a stray laser blast. Bucky was inside, sitting on the toilet as usual, he thought the trailer blew up because he had too many Mexican brunches.
In the episode "Sleepover and Over", the trailer did happen to have a separate bathroom which Timmy used to talk to his fairies.
Apparently, Chester's trailer never moves, despite having wheels.