I'm not sure who is responsible in WA. I think the majority of sno-parks in OR are plowed by OR Dept of Transp (with instructions from the managing Forest Service).
An alert from ODOT was issued yesterday saying that sno-parks and secondary highways would NOT be plowed this coming weekend. The priority is major highways/interstates. They have been at it so much this week, they are now encountering equipment failures...which is only going to delay ALL plowing even further.