Montana

BOOTSY: I spent a summer training horses in Montana.

Montana is the fourth-largest US state, situated in the north west region of the nation. Its name is from the Spanish for “mountainous country”, and the Rocky Mountains are in the west of the state, while the eastern side is characterised by prairies and badlands. It is sometimes called “Big Sky Country”. The economy is primarily based on agriculture, including cereal crops and ranching. Dude ranches are common here, and it’s possible that Bootsy is exaggerating a summer vacation on a dude ranch as “working with horses”.

EDIT: Thanks to sharp-eyed reader melcauble for pointing out a silly error in this entry, where I accidentally wrote Rune instead of Bootsy!