A Birder's Guide to Washington covers the entire state and includes detailed site descriptions with good maps. There is an excellent annotated checklist showing seasonal occurrence and tips for finding specific species. This is the guide used by serious local birders. The book is online and also available in book form.
Great Washington State Birding Trail maps. A project of Audubon Washington and the state chapters, these maps describe regional routes and include thumbnail descriptions of sites.
Birds of the Pacific Northwest covers more than four hundred bird species in Birds of the Pacific Northwest. Full-page accounts of individual species include range maps and over nine hundred photographs by the region’s top bird photographers.
Birds of the Puget Sound Region is a pocket-sized photographic guide featuring over 260 species of birds. Designed for beginning and experienced birders.
Birding in Seattle and King County Written by Seattle birder Gene Hunn, one of the longtime local experts. This book includes site descriptions with maps and an extensive annotated checklist including occurrence charts.