the Blue Mountains /Emmigrant Hill just east of Pendleton can be very tricky weather wise. Check ODOT's web pages and they also compartmentalize each section of Oregon.

Once you make it past or down the Blue Mountain Pass (4k too) then you have the valley that La Grande is in and another hour away is Baker City which is also part of that valley. The locals say that the wind and weather whips up snow because the two towns are surrounded by mountains, and it's like being in a toilet bowl. I-84 closes a lot in the winter in that area