Are there any grebes currently in the US or Canada?
The aforementioned Red-necked Grebe at the Biodome is the most recent/current one I'm aware of. Aquarium of the Pacific had a Pied-billed Grebe in the not too distant past.
The Aquarium does still have their Pied Billed Grebe. Here’s a photo from a few months ago:The aforementioned Red-necked Grebe at the Biodome is the most recent/current one I'm aware of. Aquarium of the Pacific had a Pied-billed Grebe in the not too distant past.

They may have come off exhibit when they shut down the coastal marsh exhibit for bird flu.