WRONG!
The requirements are:
1. Made in the USA
2. At least 51% corn mash
3. Aged in charred oak
4. No less than 80 proof at release (there are other proof levels at distillation time and at the time it goes into barrels).
There's argument as to whether Bourbon refers to the Kentucky county as well.
Bourbon is recognized as a protected geographic name for the entire US, not Kentucky.
That being said, 95% of all Bourbon is indeed produced in Kentucky, but it's not a legal requirement.
And yes, I've been to both Heaven Hill (Evan Williams among others) and Makers Mark (I've got a bottle I dipped in the wax myself).