More than a mile long, the Grand Coulee Dam is the largest concrete structure in the U.S. In the fall of 2011, dam operators agreed to open the spillway just for American Experience. "It was very exciting that they agreed to spill for us for a short period specifically for the film," said Associate Producer Lauren DeFilippo. "We ran to the top and bottom [of the dam] in about 30 minutes to capture all that we could" on film.

This 15-second time-lapse video shows the spillway closing. The water flowing through the spillway makes the Grand Coulee appear white, though when the water stops, the concrete appears black.