How much time do you plan on spending in the area? Fyi, Lost Lake tends to get really busy in the summer months so if you plan on camping up there try to make it mid week. Timberline is always fun to go and hang out, can't go wrong there. Lots of great riding, the old historic Barlow Rd. is really fun and there are good camp spots along the way if needed. If nothing else you can spend a day in Hood River brew pub hopping and eating.
Hope all goes well and feel free to reach out for more info.