Portrait and Biographical Record of Saginaw and Bay Counties. (Chicago: Biographical Publishing Co., 1892).
Martha Hay--Saginaw's Female Lumber Baron, Mid-Michigan Remembers website, Delta College.
On lumbering in Michigan see, Jeremy Kilar,
Michigan's Lumbertowns: Lumbermen and Laborers in Saginaw, Bay City, and Muskegon, 1870-1905. (Wayne State University Press, 1990).