In June, with our 40' motorhome we stayed at Joseph H. Stewart State Rec Area on Hwy 62 near Prospect. We drove there from I-5 at Medford. It was very nice and nice biking/hiking trails. It was 1/2 hour drive to Crater Lake. If coming from Hwy 97, Collier Memorial State Park is also very nice. It's near the intersection of Hwy 62 at Chiloquin. Another way to get there is coming from I-5, Hwy 138 at Roseburg is a good drive. It would take you to Diamond Lake where there's a RV park and a forest service campground. I've heard the mosquitoes can be very bad there. Crater Lake Nat'l Park also has a dry campground but I don't know the size recommendation. It's at the entrance of Crater. I wouldn't take your RV to drive the circle loop around the lake - too much congestion and very narrow road. The drive takes about 3-4 hours to complete with viewpoint stops. The lake is gorgeous and well worth a trip!
Full-Timed for 16 Years
.... Back in S&B Again
Traveled 8 yr in a 40' 2004 Newmar Dutch Star Motorhome
& 8 yr in a 33' Travel Supreme 5th Wheel