Frank Jay Haynes, known as F. Jay or the Professor to almost all who knew him, was a professional photographer, publisher, and entrepreneur from Minnesota who played a major role in documenting through photographs the settlement and early history of the great Northwest. He became both the official photographer of the Northern Pacific Railway and of Yellowstone National Park as well as operating early transportation concessions in the park. His photographs were widely published in articles, journals, books and turned into stereographs, and postcards in the late 19th and early 20th century.