Butterflies & Bulldozers (2010) 2010, Documentary, History, United States Butterflies & Bulldozers (2010) Duration: 1H2M Description: San Bruno Mountain is the largest intact fragment of wild San Francisco. For fifty years, many people have fought to protect the mountain and its rare butterflies. The fight resulted in a significant change to the federal policy o….. Trailer ↗ United States 2010 Documentary History