When the Last Tree Dies — Kate Taylor

When a doomsday cult destroys the nation-state of Mercanto Valley, the survivors escape to the high mountain valleys of the Capucin wilderness. With the help of a diverse group of settlers who came before them, they try to build a better world by avoiding the mistakes of the past. But the cult's remaining followers have established a totalitarian regime in one of the canyons, and the survivors once again find themselves under threat of annihilation. With the help of an ancient Druidic monastery, and a community of artists who settled the upper valleys, they learn to reconnect with nature so they can become strong enough to fight back with peace instead of violence.