Have a great trip. Hope you post some great shots from your visit here as well. Take care,

Gary

Hey John,
Most of my best friends & family live in Aus but I've never been. Looking forward to the day I do. Anyway, I live about 5 to 6 hrs from both parks. Both are open year round. Crater Lake NP would have the colder weather in Mid May. While I wouldn't worry too much about getting snow bound, it can get very cold, but for the most part during the day, you can get by with just a pullover & a few layers under that. I have a friend who live in Crescent City, CA. She is over in Redwood NP all the time. There's just too many great places to see them all unless you have 6 months to a year. Let me know, if you need any other help and I'll see what I can do.