Four thousand feet below the canyon rim, the Colorado River continues to slowly eat away at rock formations that created this vast and awe-inspiring canyon.
But this is not the Grand Canyon tourists have come to know and love. This is Grand Canyon West, 90 miles downstream from Grand Canyon National Park, on land owned by the Hualapai Indian Tribe.
Now, the Hualapai are about to do something no one has ever dreamed of before.
Later this month they will open Skywalk -- a $40 million glass and steel platform that allows visitors to walk out 70 feet from the canyon's edge and look straight down into the canyon and river below.
"It's an engineering marvel of the world," said Robert Bravo, a Hualapai Indian who is the operations manager of Grand Canyon West.
Equipped with glass side panels and a sturdy railing, Skywalk's floor is fabricated out of five layers of tempered glass. The walkway is 10-feet wide and forms a horseshoe that juts out from the rim.
Two steel box beams support the structure, and there is a concrete track and 8 concrete columns reinforced by cement and rebar. Skywalk is secured by 108 "micro-piles" that were sunk 30 to 40 feet into the bedrock.
"It's massive," said project superintendent Don Highsmith. "There's over two million pounds of structure here."
Engineers say Skywalk can support 6 dozen 747's, though no more than 120 people will be allowed on it at any given time.
It will be closed during bad weather even though it's engineered to withstand 100 mile per hour, hurricane-force winds.
"I would definitely be afraid to walk on it," said Terry Caldwell from Indianapolis. "It would make me nervous."
His wife, Suzanne is more adventurous.
"We live in Indiana, it's very flat there so this is very special," she said.
Not everyone approves of this audacious feat of engineering. Environmentalists and some tribal elders condemn it as a desecration of a sacred American landscape.
"The Grand Canyon deserves much better," said Robert Arnberger, former superintendent of Grand Canyon National Park. "Skywalk is nothing more than a thrill ride, or thrill walk, hanging over the edge."
"It's sacred ground," said Delores Hunga, a Hualapai Indian dancer who was born near the canyon 70 years ago. "Where I stand and dance, this is sacred ground."
For the 2,200 member Hualapai Tribe, which has tried other ventures including casino gaming only to fail, Skywalk represents a last chance to pull themselves out of poverty.
"This hopefully will benefit our people," said Wilfred Whatoname. "It's for our children, their education."
"We definitely need this," echoed Bravo. "It's going to create more revenue, more jobs for our kids, now and later on."
In nearby Peach Springs, Ariz., the capitol of the Hualapai nation, rusting old cars, stoves and refrigerators litter the scrubby front yards of dilapidated one-story homes.
"I understand the purpose of it," said Drake Havatone, whose family dominates the Hualapai tribe. "But I just don't like it. Once you start messing with nature, then you're messing with something more powerful than man."
Construction costs for Skywalk and a faux Wild West town (complete with shoot-'em-up cowboys, but no Indians) has approached $40 million.
A new $45 million airport funded by the federal government is also being built. And the tribe is not paying for construction of the skywalk, either.