Yes, your junco is an "Oregon" Dark-eyed Junco. I am not familiar with name Cassiar junco. Oregon's are rare, but regular in Pennsylvania. I have only seen a handful of them in Erie County and only a couple were males.
This is a female slate-colored junco chomping on a sunflower seed. This cute little female adorned one of my Christmas cards from last year.
As the afternoon wore on it started getting pretty cold and windy...
so I headed indoors for some hot coffee and a cozy warm blanket!