Why is Alcatraz an abandoned prison?

It's abandoned because it cost too much to keep it running. Costs due to everything (inmates, supplies etc) having to be shipped by boat was one of the main reasons. That and the fact it was crumbling to the ground due to the caustic salt water surrounding it deteriorating the concrete and steel. read more

Alcatraz can not be considered "abandoned". For 19 months, in 1969-70, it was occupied by a group of American Indians, who claimed that it was Indian property. They were eventually dispossessed, and eventually the penitentiary was turned over the the National Parks Service. read more

Alcatraz Island is home to the abandoned prison, the site of the oldest operating lighthouse on the West Coast of the United States, early military fortifications, and natural features such as rock pools and a seabird colony (mostly western gulls, cormorants, and egrets). read more