it's odd to me that you'd expect a large stock of English books in any regular Thai library
even in Japan, with perhaps the very strongest reading culture in the world, you're going to find a relatively limited selection of books in library outside of their own language
you'll likely have less success finding a varied stock of Thai books in Oregon, to the surprise of nobody
There are hundreds of great ones, but Tale of Genji (classic), The Master of Go (amazing if you like the board game Go), Coin Locker Babies (Ryu Murkami > Haruki Murkami), Out by Natsuo Kirino.
even in Japan, with perhaps the very strongest reading culture in the world, you're going to find a relatively limited selection of books in library outside of their own language
you'll likely have less success finding a varied stock of Thai books in Oregon, to the surprise of nobody