Mid-weight fleece top and pants. Wool or fleece ski hat. Light weight gloves or mittens. Wool is great. It keeps you warm even when wet, but it is bulky and heavy.
Fleece is superior to wool.
It keeps you warm when wet and dries quickly. The above items are your foundation in the high mountains, even in summer. They will keep you comfortable and safe. Remember that for these items in particular, it's better to have them and not need them, then to need them and not have them. Heavy weight fleece top.