While a student there he participated in a three-month scientific expedition to Laysan, one of the Northwestern Hawaiian Islands.
[1] After graduation in 1916, Bailey served as curator of birds and mammals at the Louisiana State Museum in New Orleans (1916–1919).
From 1926 to 1927 he was on the staff of the Field Museum of Natural History in Chicago, during which period he took part in an expedition to the Semien Mountains of Ethiopia.
[1] Bailey returned to the Denver Museum as Director in 1936, a position he served in for over thirty years, eventually retiring in 1969 at the age of 75.
He was also a popularizer of science and a skilled photographer, producing the Denver "Museum Pictorial" series of booklets, and contributing articles to magazines such as National Geographic and Natural History.