No road leads up to or over Rainbow Bridge, and no hands built it.
The reddish sandstone of the Colorado Plateau instead was washed away by the forces of water, sculpting a natural arch that takes hours to reach whether by boat, foot or horse.
The isolation of the bridge in far southern Utah kept it secret from many outside the area. But its proclamation as a national monument 100 years ago this year opened it up to visitors to explore its beauty and learn about its rich geological and human history.
"Celebrating that monument status is special in many regards, and I invite visitors to try and just grasp some idea of what the American West will be like in 100 years," said Chuck Smith, an interpretive ranger for the National Park Service and the monument's only full-time employee.
Some people choose to hike 18 miles from the northeast side of Navajo Mountain or the 16 miles from the Rainbow Lodge ruins on the southwest side of the mountain. The lodge burnt down in 1951, which then co-owner Barry Goldwater blamed on a cowboy smoking in the back room. Teddy Roosevelt was part of a horseback expedition to visit the bridge in 1913.
But today most of the 90,000 annual visitors take a much easier route, by boat from Page, Ariz., which upon arrival requires only a short hike. The 50-mile water trip across Lake Powell, made possible by the creation of Glen Canyon Dam in the 1960s, gives way to views of cathedral-like canyons and geologic formations that are hundreds of millions of years old.
Smith greets visitors after their two-hour boat ride to the bridge. Aside from a Park Service ranger, a trail, a shaded canopy and, Smith jokes "nice comfy La-Z-Boy rocks," the monument is much the same as it was hundreds of years ago, he said.
"You don't see interpretive signs or text on side," Smith said. "All you see is what should be reflected there, the ambiance — that isolated slice of the Colorado Plateau."
There he tells stories of early explorers who trekked days through rugged terrain to reach a bridge they had only heard about. The hiking trails remain rough to this day. President William Taft later would proclaim it a national monument on May 30, 1910, saying it "is of great scientific interest as an example of eccentric stream erosion."
Though expansions were proposed over the years, the monument retains its original 160-acre boundary. Smith carries around a photo of people standing atop the bridge, when that was allowed, to give visitors an idea of the scale of the towering arch that measures 291 feet tall and 275 feet across. He considers it the largest natural bridge in the world, though that is debatable.
The bridge is tucked at the base of Navajo Mountain, about 8 miles north of the Arizona state line. Five Native American tribes in the area consider it sacred. Two Native guides led an exploration party there in 1909, whose goal was to have it set aside as a national monument.
Wally Brown, a Navajo man from Page, said tribal members have made offerings for thousands of years to deities at the bridge, praying for rain, bountiful harvests and food for livestock. "It was a place where our old people believe they could be near the creators," said the 64-year-old Brown.
Accessibility to the site Navajos refer to as "the big rock that arches across the heavens" has changed since its proclamation as a national monument, but Brown said he is hopeful it inspires people to learn about Native people, their culture and to respect it.
"People who are sincere can look at that national monument and say, 'there were people here hundreds of years ago, and they're still here, and a culture has sustained them,'" Brown said.
The monument is administered by Glen Canyon National Recreation Area, under the National Park Service.