“We will purchase said Alcatraz Island for $24 in glass beads and red cloth, a precedent set by the white man’s purchase of a similar island about 300 years ago,” read their proclamation. That other island was, of course, Manhattan, bought from Native Americans by the Dutch in 1626.

Soon after their arrival, the group found buckets of terra-cotta-colored paint, believed to be left over from the nearby Golden Gate Bridge. Some took to spelling out declarations of native sovereignty and painting raised red fists on the island’s dilapidated prison buildings, including the water tower.

The park service spent most of a year and $1.5 million restoring the 250,000-gallon tank and 103-foot steel tower. The task included carefully matching the graffiti’s paint and inviting Native Americans to participate in tracing over the final block letters. Park service employees say that in the month since the project’s completion they have noticed a significant rise in the number of tourists who see the graffiti and ask questions about it.

Still, most of the 1.4 million visitors who come to the island each year come for the intrigue of the federal prison years. From 1934 to 1963, the prison held some of the nation’s most notorious criminals, including the mob boss James (Whitey) Bulger, George (Machine Gun) Kelly, and the “Birdman of Alcatraz,” Robert Stroud. “Most people don’t know anything about our history here,” said Eloy Martinez, 72, a member of the Southern Ute tribe. “They just come over here to get their pictures taken next to Al Capone’s cell.”