Customs in Seattle or Vancouver?

[auntjoy036]

I am flying from Atlanta to Vancouver later this month. The legs are Atlanta to Seattle then Seattle to Vancouver. I flew this route a few years ago but can’t remember if I have to pick up my checked bag in Seattle, go through customs, then check the bag back in or if the Seattle layover is like a US domestic one and all customs/immigration tasks happen once I land in Vancouver. I would appreciate help from those familiar with similar itineraries. 
 

I am scheduled to be in Seattle for about an hour and a half. That is plenty of time if I just have to walk from one gate to another but tight if I have to claim and recheck a bag.

 

Thanks for your help.

[d9704011]

Seattle is like a domestic stop.  You won't see your luggage (hopefully) until you reach Vancouver.

[auntjoy036]

@d9704011, Thank you.