This was on July 1 attempting to cross Elk Pass near Randle WA. The slushy snow was up to the hubs. It was in the 80s in the valley. This is a FS road which are not plowed like regular roads thanks to budget cuts so check with the FS before attempting passes on their terrain. See http://www.crazyguyonabike.com/doc/petejack02 I ended up making a very long detour to get back on trail at Cascade Locks. ( Some kind correspondent with local knowledge told me I couldn't have picked a worse route to the Locks. See the correspondence in the CGOAB article.)
You'll probably be able to get across Crater Lake NP but not be able to ride round the lake if it's a heavy snow year. That's what happened to me.
(Edit. Sorry my pic doesn't display. Dunno why, it did in the preview before. Go to my CGOB link to see pics)