Blue jay.
Could be a indigo bunting, male
Beautiful bird but note the feather in question has marks of barring, which this bird doesn't show. Jays jave barred feathers though
Looks like it could be Steller's Jay.
The US Fish & Wildlife Service has a feather atlas to help people ID North American birds.
It’s not perfect as they may only have feathers from one or two individuals, and like people birds of the same species aren’t all identical. But it’s still a good resource. Plus it has an Identify My Feather feature that’s fun and interesting to use.
What is this thing?
Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.