Okay, but with all this flour, where is the yeast? I've actually been lucky to find plenty of flour at the local Mexican or Asian markets. Yet, no where I look

Okay, but with all this flour, where is the yeast? I've actually been lucky to find plenty of flour at the local Mexican or Asian markets. Yet, no where I look have I been able to find even a tiny package of yeast. It's out all over the place.