Natural Bridges [AAW06]

Specifically Natural Bridges National Monument. Not the only place to see rock spanning a stream, but a nice place to do so. It seems to be a less visited attraction in the Utah slick rock country. The road was paved in 1976 (a travesty of industrial tourism) so it has always been a bit remote. Easy to find though. It's in White Canyon. You'll find it nestled into the Permian Cedar Mesa Sandstone between the spectacular road cut down Comb Ridge and the bar at Fry Canyon Lodge (assuming it is still a going concern).

The Cedar Mesa is another eolian sandstone. A sand dune deposit believed to have been near a sea shore. During the Permian period (299 to 251 million years ago) all the continents were joined together in a supercontinent called Pangea. What is now Utah was then a bit closer to the equator and oceanfront property. At the end of the Permian, life was almost snuffed out on earth. Something like 90% of all marine species and 70% of land animals disappeared. "The times, they are a-changing..."

The white sandstones of the Cedar Mesa give White Canyon its name. Imaginative.

I spent the afternoon checking out the bridges before meeting up for a week-long backpacking trip in the archaeological wonderland of the Grand Gulch Primitive Area. This post is about Sipapu Natural Bridge. If you visit, do check them all out. Here's a view of Sipapu Bridge from the upstream side.

Sipapu Natural Bridge, White Canyon, Natural Bridges National Monument.

The trail down to Spiapu Natural Bridge is a nice, even and well maintained. There are a couple of steep sections that are negotiated with stairs and ladders to add a bit of interest to getting down and back up. Anyone in reasonable physical condition can easily do this walk. Don't let the warning signs deter you from a splendid afternoon stroll.

This view of the bridge shows the path someone could take if they wanted to actually use the bridge to cross the stream. Although, the killjoys at the NPS likely frown on such actions. Still, it would be an interesting view from up there looking down the canyon. The bridge does not actually span all the way across the canyon (see image above) so you would have to access it from the side of the canyon opposite the trail access. An interesting walk I'm sure.

Sipapu bridge was formed at a meander in the stream which eroded White Canyon. The stream was flowing roughly southwest down the canyon and made a hard left turn then back to the right and another hard left. This resulted in a sandstone wall or fin extending into the canyon from the north rim. The sandstone fin withstood the river erosion for a few million years - enough to entrench a canyon a little less than half of what it is now. This up-canyon view shows the modern day stream course flowing under the bridge. The ancient stream course turns to the right into the bridge shadows and flows around the buttress on the right about half way to the top of the bridge.

Sipapu Bridge looking upstream (northeast).

After digging out an approximately 100-foot deep canyon, the river found a sufficiently erodable bit of the rock fin sticking out into the canyon and began to remove the middle section of the base of the sandstone neck. As the base was undermined, overlying rock fell into the canyon and eventually made an opening for the stream to flow through. The stream then continued eroding the canyon while flowing through the bridge with a 220+ foot natural bridge as the current result. So far, the last bit of rock at the top has not collapsed into the canyon. For now, it is the second largest natural bridge in the world. Rainbow Bridge, a few miles to the south, is the largest.

A view from a bit lower in the canyon showing the meanders upstream gives a hint into the impermanence of a natural bridge.

This temporary formation will soon enough be worn away and the stream will continue is excavation of the canyon. How many bridges must have existed in the past, but have since been eroded? Unknown, but an entrancing question.

Hopefully your visit will be on a spring day with plenty of sunshine and only a few fellow hikers. Spend some time at the bottom of the canyon. Listen to the birds. The breeze. Your breath. Enjoy the delicious taste of warm water from a dirty Nalgene bottle. Perhaps a handful of peanuts and raisins from a sandy, sweaty hand. Water, food and the awe of experiencing and understanding the world. Three of the 5 essentials of a good life (I would add love and friendship to round out the list). And, coincidentally, two of the 10 essentials for hiking.