That's a northwestern garter, they are very rarely bred and have so many patterns/colors available you'd be hard pressed to find anyone who ends up breeding one that looks just like that. They are one of the most naturally variable snakes in the world IMO.

Also I am not sure you can keep species native to Oregon anymore, they recently changed some native wildlife laws pertaining to reptiles. There are still many dozens of garter species/subspecies available that are not native to Oregon though.