Construction work on Barro Colorado Island, by Unknown, 1939, Smithsonian Archives - History Div, Three unidentified construction workers at the Canal Zone Biological Area located on Barro Colorado Island (BCI) are reconstructing the main laboratory using concrete blocks for the siding and for posts. The building was raised about 6 inches to make it more convernient for taller people. BCI was created when the Chagras River was dammed to create Gatun Lake as a watershed for the Panama Canal. The mountaintop island was set aside as a preserve for visiting North American naturalists. It was funded by a consortium until 1946 when the Canal Zone Biological Area was transferred to the Smithsonian and later renamed the Smithsonian Tropical Research Institute..