Eagles usually mate for life, choosing the tops of large trees to build nests, which they typically use and enlarge each year. Bald eagles may also have one or more alternate nests within their breeding territory. In treeless regions, they may also nest in cliffs or on the ground. The birds travel great distances but usually return to breeding grounds within 100 miles of the place where they were raised.
U.S. Fish and Wildlife Services; https://www.fws.gov/midwest/eagle/Nhistory/biologue.html
