One of the seven wonders of the world can be found in the canyon-lands of southeastern Utah. RainbowBridge is the world's largest natural bridge, standing 290 feet tall and spanning 275 feet; the top of the bridge is 42 feet thick and 33 feet wide. RainbowBridge is made of salmon-pink sandstone, with dark red and brown vertical streaks of iron ore. These particles, called "desert varnish," may have leached from the rocks, or they may have been carried by the wind as dust that stuck to the moister areas of the rock. Subtle shades of purple and orange are brought out by the afternoon sunlight, turning the bridge into a rainbow of stone.
For many Native Americans, RainbowBridge is a sacred place. The Navajo believe rainbows represent the guardians of the universe. The base of RainbowBridge was built by nature hundreds of millions of years ago, as layers of reddish-brown sands and muds, called Kayenta Sandstone, were deposited and compacted. The span of the bridge, composed of Navajo Sandstone, was formed as wave after wave of sand was deposited, forming dunes up to 1,000 feet high. Over the next 100 million years, the base and the dunes were buried under more than 5,000 feet of rock layers. The heat and immense pressure further compacted and hardened the rock of these formations.
Around 60 million years ago, the area now known as the Colorado Plateau began to uplift. Streams cut into and eroded the layers of rock as they lifted above sea level. As these massive layers rose and tilted, streams gained more momentum and force. Water flowing off Navajo Mountain formed Bridge Creek. As the creek meandered toward the Colorado River, it slowly eroded the sandstone, creating thin rock walls as it nearly looped back on itself. Rushing water during floods pounded away at the walls until the loosely cemented Navajo sandstone gave way, creating a hole. Over the centuries, as the creek flowed through the hole, it continued to work away at the sandstone until RainbowBridge was formed.
Most people travel by boat from LakePowell to the rather remote RainbowBridgeNational Monument, though it is possible to hike a grueling 13 miles to reach the monument. Hikers must get a permit from the Navajo Nation and should carry the topographical "Navajo Mountain Quadrangle Map," available from the Park Service. Hiking either to and from or just around the 160-acre monument allows visitors to experience some of the spectacular scenery of the Colorado Plateau. Steep rock walls form a labyrinth of canyons -- some dry, some alive with cottonwood, ash, western redbud, serviceberry, and other plants.
RainbowBridgeNational Monument Information
Address:GlenCanyon National Recreation Area and Lake Powell, AZ/UT Telephone:928/608-6200 Hours of Operation:The monument is open year-round. The visitor center at GlenCanyon is open, Labor Day to Memorial Day and the rest of the year Admission:Free; permit required to hike trails