On August 20, 2005, in a private ceremony, Thompson's ashes were fired from a cannon atop a 153-foot (47 m) tower of his own design (in the shape of a double-thumbed fist clutching a peyote button) to the tune of Norman Greenbaum's "Spirit in the Sky" and Bob Dylan's Mr. Tambourine Man.[31] Red, white, blue, and green fireworks were launched along with his ashes. As the city of Aspen would not allow the cannon to remain for more than a month, the cannon has been dismantled and put into storage until a suitable permanent location can be found. According to his widow Anita, Thompson's funeral was financed by actor Johnny Depp, a close friend of Thompson. Depp told the Associated Press, "All I'm doing is trying to make sure his last wish comes true. I just want to send my pal out the way he wants to go out."[31]

Other famous attendees at the funeral included U.S. Senator John Kerry and former U.S. Senator George McGovern; 60 Minutes correspondent Ed Bradley and Charlie Rose; actors Jack Nicholson, Bill Murray, Benicio del Toro, Sean Penn, and Josh Hartnett; singers Lyle Lovett, John Oates and numerous other friends. An estimated 280 people attended the funeral.

The plans for this monument were initially drawn by Thompson and Ralph Steadman and were shown as part of an Omnibus program on the BBC entitled Fear and Loathing in Gonzovision (1978). It is included as a special feature on the second disc of the 2003 Criterion Collection DVD release of Fear and Loathing in Las Vegas (labeled on the DVD as "Fear and Loathing on the Road to Hollywood"). The video footage of Steadman and Thompson drawing the plans and outdoor footage showing where he wanted the cannon constructed were planned prior to the unveiling of his cannon at the funeral.