Flight
The airport in Medford, Oregon, is the closest airport to Crater Lake. Sometimes two one-way tickets are cheaper. It depends...
Rental Car
Car rentals in Medford are about $200-$400 a week.
House Or Rental
We rented a cabin from Airbnb near the towns of Trail and Prospect. Most cabins and houses for rent around the area are within an hour from Crater Lake. Below are some links to places around Prospect if you are interested. https://www.airbnb.com/rooms/11420557 https://www.airbnb.com/rooms/13147732 https://www.airbnb.com/rooms/19210820 https://www.airbnb.com/rooms/24572550 https://www.airbnb.com/rooms/14539229 https://www.airbnb.com/rooms/21622757
House Or Rental
VRBO & Airbnb have some of the same listings. The prices are about the same, but sometimes one place will be cheaper on the other site. Copy and paste links (sorry). https://www.vrbo.com/82682 https://www.vrbo.com/789296 https://www.vrbo.com/1368904 https://www.vrbo.com/869377 https://www.vrbo.com/1028381 https://www.vrbo.com/955519
Hotel
Crater Lake Lodge is the only lodging available within the Crater Lake National Park. It may be fully booked already, but sometimes there are cancellations.