At the time of his death in 1935, Harry S. Swarth, head of the Mammalogy and Ornithology Departments at the California Academy of Sciences in San Francisco, had been preparing a manuscript reflecting on twenty-five years of his research in coastal Alaska and British Columbia. "The Distribution and Migrations of Birds in Adjacent Alaska and British Columbia" summarized Swarth's research, ideas, and conjectures on the bird life in the region, including theories about when and how birds populated this vast territory after the retreat of glaciers near the end of the Pleistocene. Drawing on his field experiences and his forty published scientific papers, Swarth's manuscript represented state-of-the-art science for the time. And his ideas hold up; his papers are still cited by ornithologists today.

In 2019, Christopher Swarth, Harry's grandson and a scientist in his own right, discovered the forgotten manuscript. This book includes the original unpublished manuscript, accompanied by contextual essays from contemporary ornithologists who examine the impact and relevance of Swarth's research on coastal bird diversity, fox sparrow migration, and the systematic puzzle of the timberline sparrow. Expedition maps display field camps and exploration routes, and species checklists illustrate the variety of birds observed at key field sites. To bring additional color and insight, The Origin and Distribution of Birds in Coastal Alaska and British Columbia also includes excerpts from Harry Swarth's field notes, a comprehensive list of Harry Swarth's publications, and a glossary with historic and contemporary bird names. Naturalists, ornithologists, birders, and all those who want to learn more about the natural history of the region will delight in the rediscovery of this long-lost treasure.