8 0.5 (4.8)
You won’t get a very good view of Kachina Bridge here, but you will find it much easier to understand how bridges are formed if you walk out to the canyon rim. There is no trail, but it’s an easy walk without unusual hazards other than the ever present cliffs. Remember, DON’T WALK ON THE CRYPTOGAMIC CRUST!
Desert Varnish
[Desert] varnish, the dark streaks on the canyon walls, is common in arid areas such as this. Each time the rock gets wet, some moisture is absorbed by the rock. Water actually seeps into tiny spaces between the grains of sand. Later, the moisture is drawn out of the rock and evaporated by hot, dry air. While inside the sandstone, however, the water dissolves minute amounts of minerals like iron and manganese. When the water comes to the rock surface and evaporates, the minerals come with it—but the minerals do not evaporate. They accumulate on the surface of the rock over thousands of years, slowly forming a very thin dark crust.
White Canyon
Notice the long, curving, fairly level valley right below you. This is an important part of the bridge formation story, for that valley was the stream channel before Kachina Bridge was formed. The stream now flows through the hole under the bridge, of course, but before there was a hole the water had to run around this side of the mass of rock that now forms the bridge. Every time White Canyon flooded (which is every time it rained very much), the stream cut a little deeper into the base of the rock and most of the cutting took place right where the stream was forced to turn toward you. As flood waters roared around this curving valley, the shape of the canyon also threw them against the downstream side of the obstructing wall of rock, so that the stream was eating into both sides of a fairly thin wall. It eventually ate right through the obstruction, and from then on the stream followed the shorter, straighter route. Continued erosion enlarged the opening and cut the channel deeper into the canyon. Downcutting of the new channel left this old channel high and dry. And there it sits!
Actually, the water coming down Armstrong Canyon (on the left) also contributed to bridge development, but we’ll get into that at a [later stop].
Kachina Bridge
9 0.3 (5.1) Kachina Bridge, viewpoint and trailhead
Kachina is an excellent example of a young bridge. The thick, heavy span crosses a relatively small opening. The span and abutments are massive, not slim and graceful.
Pictographs
Below the bridge are ancient pictographs (drawings on stone) that some people felt represented or at least looked like the Hopi Indian gods called Kachinas. So the original name was discarded and “Kachina” was substituted.
As at the other bridges, there is a very nice little trail down into the canyon. The trail is in good condition, you can walk it without special equipment, and it isn’t especially strenuous. It is a bit steep, so coming back on a hot day you may find the trip can be tedious. If the weather is fairly warm or hot today, you may also want to take water. An hour or hour and a half is adequate time to allow for the trip—unless you fool around a lot.
9
A The Monument landscape is typified by hundreds of ledges and shelves separating the cliffs. Nearly all the canyon walls are lined with such ledges. That is because the rather hard Cedar Mesa sandstone is seamed with many thin layers of relatively soft rock. The softer material erodes very much faster, and as it wears away, the rock above and below it is also exposed to the elements. As a deep horizontal crevice develops, support for the rock above it is removed and chunks eventually fall out. In time, a wide ledge (or shelf, or bench, or whatever) forms.
All of the above is happening here, right in front of you. This isn’t just an interesting formation, it’s a dynamic, continuing process that is changing the landscape.
9
B The canyon coming around the corner on your left is Armstrong Canyon. It joins White Canyon on your right. In front of you is a waterfall (or it would be there if any water was flowing) above a deep, narrow plunge pool. This type of thing is often called a “nick point,” and it is evidence of some abrupt change in the canyon’s development. In this case, that change was probably formation of Kachina Bridge, which changed the gradient, or steepness, of the stream. The water, rushing over the lip and plunging into the pool, quarries out a hollow under the lip. In time the lip breaks off, the waterfall moves back a few feet, and the process goes on. A similar, but somewhat larger nick point is Niagara Falls.
If the canyon is dry today, it may be a little difficult to believe the explanation. If you could be here just after a heavy rain, when the flood thunders over the rocks at a rate of thousands of gallons each second, you would find the whole thing more believable.
Nick Point
Little Arch
9
C This little arch (it’s not a bridge) may not win prizes for size, but it is very handy for helping explain bridge or arch growth. A bridge is first formed by the action of running water, but much of its subsequent growth is like development of an arch. Water seeps into tiny cracks, freezes in winter, and pries flakes or blocks of stone loose. Alternate heat and cold causes rock to expand and contract and that opens little cracks, causes tension, etc. If the rock has natural planes in it, it may break away along those lines.
If you look at the underside and sides of this little arch, you can see evidence of these processes. Please don’t “help nature along” by prying pieces loose.
This arch may not have been here very many centuries, but it is a very “old” arch. Thin and delicate, the fragile span over a relatively huge opening is near the end of its life.
9
D Back when we explained bridge formation and abandoned meanders, we said Armstrong Canyon’s run-off played an important role in Kachina’s development and that we would explain it “later.”
[Well,] now is later. Before the opening was formed, while White Canyon run-off came around the channel on your right, Armstrong Canyon run-off flowed down the channel from your left and rushed right against the rock wall that once existed where the opening now is. Flood waters roaring down Armstrong would rush out its mouth, cross the White Canyon streambed, and smash into that rock wall. Floods carry great loads of sediment: sand, gravel, pebbles, rocks and boulders. These are the teeth of a flood, the sand and boulders. They are the agents of erosion that bang, smash and batter any obstruction. It is a bit like a liquid saw with stone teeth. It’s an act of violence, a cataclysm, a ripping and tearing. There really isn’t anything nice or gentle about it, but it’s a great way to undercut rock walls and gnaw holes in them!
And that is precisely what it did.
Well, that’s about enough for a while. You are more than halfway through the Monument and we’ve been telling you what to see, do, and think entirely long enough. Go now, and just enjoy the rest of this lovely walk. Walk the trail in leisure and peace. At the bridge are ancient ruins and irreplaceable prehistoric rock art. Let them speak to you, respect them, and consider your long gone predecessors here. Consider your place here, too, and the role you play in our beautiful little world.
BEWARE! And go cautiously, for there are spirits here that will make you part of this land and forever call you back!
Ancient Ruins and Rock Art
10 2.0 (7.1) Owachomo Bridge viewpoint and trailhead
Owachomo is a lovely bridge. Long, thin, flat; a fragile old bridge nearing its logical and inevitable end: collapse. The opening grows very slowly under an old bridge. The opening widens as the bridge abutments wear away and the overhead span (the bridge itself) becomes thinner and thinner, one grain of sand at a time.
The walk down to this bridge is the easiest of all. You can be down and back in a half hour (as usual, we recommend that you take longer). It is not strenuous, compared with the other two, and it offers some nice insights about bridges. In other words, here’s another different point of view. Owachomo is sort of a different kind of natural bridge, for it was formed differently than the others. We’ll explain that when you get down there.
10
A We haven’t said very much about wildlife here, mostly because you aren’t likely to see much of it. Here however, you can see the work of a porcupine. Porcupines like to eat pinyon bark at times, and this pinyon must be pretty tasty. The large rodents gnaw at the tree to get at the nutritious inner bark, and may in time kill the tree by girdling it. The inner bark carries needed food and water between roots and leaves (both up and down), and if all the lifelines between the top and bottom of the tree are severed, the top will die.
No, we don’t try to “protect” the tree from porcupines. We call this a natural area, and that means it is an area where we try to let natural events proceed without the interference of man. That isn’t just “protection” of things, it’s protection of a system. It just means that if the porcupine wants to eat the pinyon, let him do it. It doesn’t mean the porcupine is “worth” more than the pine, nor vice versa. Each has its own place, its own life, and its own interactions with the rest of the world. Just like you do!
10
B This is a good place to consider Owachomo’s origin and evolution.
Run-off from a large area used to flow down the little canyon (Tuwa Canyon) in front of you, along the base of a rock fin, and into Armstrong Canyon behind you to your right. Owachomo did not exist; there was no natural bridge at that time. Flood waters rushing down this side of the fin ate into the base of the fin and flood waters of Armstrong Canyon ate into the other side. A hole developed in the fin, creating the bridge and allowing Tuwa’s run-off a shorter route to Armstrong.
So, Owachomo was formed by the action of two separate streams, and that makes it different from Kachina and Sipapu (and most other natural bridges we know about).
Owachomo Bridge
Erosion is a continuing, dynamic process; however, stream channels gradually change. The run-off from Tuwa no longer flows through the little canyon in front of you because there is now a deeper canyon on the other side of the bridge fin.
10
C Passing the “Unmaintained Trail” sign isn’t like abandoning all hope, but it does mean that the trail may be harder to follow and that we don’t do as much to protect or help you. Some hikers continue from here and go all the way back to Sipapu via the canyon’s trail. Many people start at Sipapu and come out this way (which is a lot easier), but a few start here and go back. It isn’t really a terribly difficult hike, either way, and it is a lot of fun.
Owachomo must once have looked like Kachina—massive, solid, strong. Later, it was more like Sipapu—graceful and well balanced. Now it looks only like itself and the even more fragile Landscape Arch in Arches National Park.
At some time soon, one more grain will fall, a crack will race through the stone, and the bridge will be a heap of rubble in the canyon. We’ll probably run around and yell a lot when it happens, while the sand grains will quietly continue to break free and begin the next phase of their existence.
If you decide to walk on under the bridge, look behind the left abutment. There, a thin bed of the softer red stone has eroded back under the harder stuff of which the bridge is made. As erosion eats into the red-bed, removing support from the abutment, the future of the bridge becomes less and less secure. Frankly, we always feel a little nervous standing under it (where you are now) because it might collapse ... now!
As you return to your car, be aware that you may hear the death roar of Owachomo. The final, critical grain of sand may slip out of place, a bird may land on the bridge, or one of your military jets may pass at supersonic speed. However it happens, Owachomo must someday fall. And its billions of sand grains must continue their journey to another resting place, and that’s the way it ought to be.
11 1.4 (8.5) Maverick Point View
To your right, across what appears as a fairly level stretch of pinyon-juniper forest, the Cedar Mesa sandstone is cut, slashed, incised, and divided by a bewildering complex of canyons. Slightly to the left of the “flats,” Maverick Point, Bears Ears, and long Elk Ridge (named by and for three cowboys with the initials E, L, and K, if you’d like another point of view!) form the skyline. Bears Ears, by the way, was named by Spanish explorers far to the south, from which point they look just like a bear peeking over the ridge.
12 0.6 (9.1) Sunset Point
If sunset is imminent, stay right here. Sunsets are sometimes very spectacular here.
Now go, and travel in peace, comfort and safety. Come again when the Canyon Country calls, if you can, but remember always that it remains here waiting, free, beautiful and untamed.
If you have questions about this magnificent land, stop at the Visitor Center. The men and women of the National Park Service will be greatly pleased to talk with you of this and the 300 other areas they serve for you and your children. And their children. And theirs.
Sunset Point
Solar Photovoltaic Power System
13 Solar Photovoltaic Power System
Most of the electricity used in the Monument is produced by converting sunlight directly into electricity. The process seems a little bit like magic, but it really does work. The system here is a demonstration of the feasibility of supplying small, remotely located communities with electricity without using fossil fuels to produce it. This process is liable to become very widely used within a decade, so the Natural Bridges installation is sort of a peek into the future. Exhibits and information leaflet explain the system in detail.
