 From 1881 to 1883, he worked for the Wisconsin Natural History Society as taxidermist and conservator of its collections.In 1883, the Natural History Society's collections were transferred to the Milwaukee Public Museum, and Kumlien began working for the museum in the same capacity, which enabled him to pursue his naturalist studies year round.He became a member of the American Ornithologists' Union the year it was founded (1883).