Camp Demigod is located in Leavenworth, WA which is 3.5 hours from the Vancouver and 2 hours east of the Seattle Airport.
Every Saturday night in July, Camp Demigod offers tent camping on the 23 acre property, just bring your own tent, bedding and towels ($75). Check in between 1pm-3pm on Saturday afternoon, check out on Sunday after 6pm. Reserve your tent when you register on a first come, first serve basis.
There are also over 50 hotels and private vacation rentals in www.leavenworth.org