Nik Wallenda will attempt to walk on a tightrope across the Little Colorado River Gorge near the Grand Canyon - without a tether or net - on Sunday.
'Skywire Live with Nik Wallenda' will be broadcast live on the Discovery Channel on Sunday, June 23 at 8 p.m. EDT/5 p.m. PDT.
Wallenda, who is 34, has been training for weeks for the stunt in his hometown of Sarasota.
The circus performer, acrobat and heir to the famed Flying Wallendas circus family, says he isn't afraid of walking a quarter mile across the gorge. He says one of the perks of the stunt is that he can enjoy the aerial view of the Little Colorado.