Our family loved Breitenbush Hot Springs, near Salem, OR. You can camp there or rent a cabin. It comes with 3 buffet style meals of very high quality, and soaks in the hot and cold pools of varying (and posted) temperatures. It also comes with free events that vary each week, such as yoga or dance classes, concertsm etc.
The facility is very earth-friendly. They use 100% renewable energy from hydropower and geothermal including geothermally heated cabins.
Our family stayed 2 night but wished we had booked for at least 3! Very relaxing and fun, and we made friendships with other families with children which have continued!
Shaheeda, mother of 6