It's amazing that this was a first book. It's beautifully poetic and atmospheric. The story is a sad one about the coming of age of two sisters who've dealt with great loss and abandonment and ultimately deal with it in different ways. The story is told with captivating evocative imagery. The cover of this book is one of the best I've ever seen at capturing the mood and feel of the story. I may have to buy it now. There were slow spots for me but, it's not very long so the slow spots were short lived. Here is one of my many favorite passages: 
 "Need can blossom into all the compensations it requires. To crave and to have are as like as a thing and its shadow. For when does a berry break upon the tongue as sweetly as when one longs to taste it, and when is the taste refracted into so many hues and savors of ripeness and earth, and when do our senses know any thing so utterly as when we lack it?" 
 I loved this and I'll be reading more of Marilynne Robinson's work.