The only evidence till date is the story published in the Arizona Gazette which mentioned how Kincaid made it to Yuma traveling through the canyon on the river Colorado. However, the biggest questionable issue with this whole story is that Kincaid was reported to be an avid photographer and yet no photographs exist of this incident like the hidden city Grand Canyon.
Image Source: www.telegraph.co.uk
The Hopi Indians believed that their ancestors once lived in the underworld of the Grand Canyon ruled by the chief named machete. They consisted of people with one heart and two hearts. Dissent among themselves resulted in those with one heart being expelled from the underworld who came up to the surface and loved by the Colorado growing grain and corn. A messenger was sent out from them to the temple of the sun for blessings of peace and goodwill and rain for their crops, the messenger never returned. Even today old aged Hopi follow the tradition of gazing out into the sunset to look for the messenger as they believe when he returns; their lands will be restored to them
Among engravings of animals found in the caves was the image of a heart over the spot where it was located. The tradition was recorded by artist W.E Rollins who lived with the Hopi for a year.
Image Source: nativeamericannetroots.net
Whether fact or fiction is a matter of choice. There are several controversies that have their own for and against theories and this too gained popularity on the basis of a newspaper report. Who knows what lurks deep down in the Grand Canyon?
Image Source: www.pinterest.com