Dewey Soper first travelled to the Arctic in 1923. During the next seven years he accepted three research postings on Baffin Island, each of which lasted between one and two years. In 1929 he discovered the breeding grounds of the blue goose in the southwest corner of Baffin Island. He also charted the final unknown region of Baffin Island's coastline. Later in life he worked in the western Arctic. Outside the Far North, Soper studied bison in Wood Buffalo National Park, documented bird life on the Prairies, and made a detailed study of small mammals in Alberta. Soper was the last of the great pioneer naturalists in Canada. He was also a skilled and meticulous explorer.

As a naturalist, he was a major contributor to the National Museum of Canada, as well as to the University of Alberta and other museums across the country.