Alcatraz Island 6, 2008, the Alcatraz Island Global Peace Center Proposition C failed to pass, with 72% of voters rejecting the proposition. The coastal environment of the San Francisco Bay Area has caused deterioration and corrosion of building materials throughout Alcatraz. Beginning in 2011, the National Park Service began major renovations on the island, including the installation of solar panels on the cell house roof, slope stabilization near the Warden's House and the stabilization and rehabilitation of the outer cell house walls. Recently, Alcatraz has been home to several art installations. The Chinese artist/dissident Ai Weiwei staged an exhibition which explored "questions
Alcatraz Island self-determination, in part as a result of the publicity and awareness created by the occupation. The occupation ended on June 11, 1971. The entire Alcatraz Island was listed on the National Register of Historic Places in 1976, and was further declared a National Historic Landmark in 1986. In 1993, the National Park Service published a plan entitled "Alcatraz Development Concept and Environmental Assessment." This plan, approved in 1980, doubled the amount of Alcatraz accessible to the public to enable visitors to enjoy its scenery and bird, marine, and animal life. Today, American Indigenous groups, such as the International Indian Treaty