Three Valleys is a part of The Project, a colony built on an alternate timeline where human life forms of any kind do not exist. It was founded during an ice age (18,000 BC in our calendar). The US Government sent a million people there in the 1950s and early 60s. The Project is now independent of the US government.
Three Valleys was founded by nudists and swingers. Schol includes 'hands on' Sex Education, sex in class. Seaside (the nudists) does not have this, but everyone is nude all the time. The sex is generally kept quiet from the rest of The Project (though there are rumors). Other than that, a very 1950s culture.
Danielle Tyler is relocated from her home in Tiburon Ca to the Project, settling in Valley's End. The story is about her struggles to adapt to a different world. Set in the same world as Three Valleys - Sammi.