In 1999, Forsberg embarked on a five-year personal mission to photograph and write a book documenting the migration of Sandhill Cranes, On Ancient Wings: The Sandhill Cranes of North America. His goal was to connect the lives of the cranes and their habits across the continent from western Alaska to Cuba.
Self-published in 2004, the book was the result of a five-year personal journey of 65,000 miles, 1,000 rolls of film, three 100-page journals, two file drawers jammed full of research and 13 locations in four countries. With stunningly beautiful photography, On Ancient Wings and its accompanying exhibition presents sandhills in their wild, but increasingly compromised habitats today.
Forsberg was also included in the PBS documentary Crane Song, which weaves together striking visuals and majestic sounds of the sandhill cranes' journey with the stories and insights of the people who observe these creatures, as well as landowners endeavoring to ensure a habitat that is welcoming to cranes.
Today, Forsberg continues to photograph one of the greatest wildlife spectacles on Earth every March on the central Platte.