As a graduate student, he accompanied Lieutenant Colonel George Armstrong Custer's 1874 Black Hills expedition as a naturalist but declined a similar appointment to the ill-fated 1876 Little Big Horn expedition.
He accompanied Lieutenant Colonel George Armstrong Custer's 1874 Black Hills expedition as a naturalist. This was as a graduate student. He declined a similar appointment to the ill. This was as a graduate student. He fated 1876 Little Big Horn expedition. This was as a graduate student.