Priority Pass is not an actual brand, rather it is a network of different clubs that belong to the system. You can visit their website to see the clubs in the system. Pretty much every major international airport has at least one Priority Pass partner that you can use. They tend to be more numerous at overseas airports than USA domestic airports.

Some examples would be:

LAX - Terminal 2 - Virgin Atlantic Clubhouse
Terminal 6 - Alaska Lounge
Bradley - KAL Lounge

SFO - Only Air France-KLM lounge in the Intl terminal

SLC - nothing

IAH - KLM Crown lounge and Air France Lounge