Looks like you'll have more options for YOW-DCA. US will be using some of their recently acquired DCA slots from DL for YOW service.
Great news. A few years ago there was just YOW-IAD service. Now looks to be around 6-7 daily nonstops to DCA/IAD between AC/UA/US.

Great option for YOW travellers heading to east side of USA. DCA is nice (far nicer than PHL / IAD!). Smallish nice US lounge if you have access.