What is the theme in This House of Sky: Landscapes of a Western Mind by Ivan Doig?

Another theme in the book is family life. The book begins with the author, his wife and young living in Seattle. He has made the decision to host and to harbor both his father and his grandmother. There is a familial crisis in that his father is ill. This type of thing comes up in many families, where there comes a time during which the roles change over: those who protected and raised a generation become dependent upon their own offspring who have since matured and come into 'their own'.