Sunday, September 22, 2013

Chiapas Part 14a: Cruising the spectacular Cañon del Sumidero

Massive cliffs frame Cañon del Sumidero, one of Chiapas' two most-visited tourist areas. The canyon's breathtaking walls rise as high as 1000 m (3281 ft) along its 13 km (8.08 mi) length. The park itself extends out on both sides and covers 21,789 hectares (53,841 acres) in four different municipalidades (counties). Carole and I came to the canyon on a tour from San Cristóbal de las Casas, about a 45 minute drive away. However, boat trip tickets can be purchased right at the docks of Chaipa de Corzo, the town that lies along Rio Grijalva at the south end of the canyon. The outward leg of the boat trip ends at the Chicoasén Dam and the round-trip takes about 3 hours.  For a Google map of the area, click here.

Launching the adventure

At any one time, there are several boats like this cruising the river. The craft appear sturdy, are driven by powerful outboard motors, and everyone wears life jackets. The captain sits on an elevated platform in the rear to keep an eye out for obstacles such as rocks, floating logs, or other boats. In 2009 and 2010 a series of accidents occurred involving decrepit boats and underaged or unqualified captains. The accidents resulted in six deaths and sixty-two injuries. The authorities cracked down because the incidents caused serious harm to the local tourist industry and apparently no problems have occurred since then. Our tour boat seemed safe and its captain was very competent and efficient and I had no qualms about the trip.

Shortly after leaving the docks, we passed under the Pan-American Highway bridge. This is the only vehicle bridge that crosses Cañon del Sumidero. The rather flimsy-looking wire suspension bridge in the foreground was originally for vehicles but now carries only a pipeline. The Pan-American Highway stretches from Prudhoe Bay, Alaska, to Ushuaia at the southern tip of South America. The only break is a short stretch of 100 km (62 mi) in Panama called the Darien Gap. About six months after our Sumidero adventure, we passed under the Pan-American Highway again when we took a boat tour through the Panama Canal.

Bright sunshine bathes the western canyon wall while the other wall is deeply shadowed.  The canyon is only about 1 km (0.62 mi) wide at its narrowest point. Our tiny boat seemed like a speck in the midst of this towering grandeur.  This view of the canyon is represented on the official Seal of the State of Chiapas.

Into the deep canyon

The canyon narrowed at this point as we headed into its depths. The Rio Grijalva bends as much as 90 degrees in places as it twists through the canyon. The walls seemed to grow ever higher as we chugged along in our little craft. Most of the tourists of the boat with us were Mexican, although a group of young German back-packers joined our tour in San Cristóbal. I am 5'10" and used to being one of the taller people in any group, but these slim, athletic Europeans towered over us. Even the women among them seemed like giants. Even so, we were all dwarfed by the canyon.

Life will find a way, even on sheer walls such as this. The sloping lower parts of the walls were covered by thick forest, but most of the heights above were 90 degree vertical drops with sparse vegetation clinging to the cliffs. The canyon began to form 35 million years ago when tectonic movements cracked the earth's surface. Over the millennia, the process of erosion and the force of the Rio Grijalva cut through the soft limestone, leaving this stupendous gorge.

A limestone cliff on the west side of the river is pitted with caves. In the center of the photograph is a formation that caught my eye as we cruised past. It is a shallow cave with a stalactite suspended from the overhang. Limestone is very porous and water seepage can cut through it but also can make new rock formations. Stalactites are formed when water drips down from the roof of a cave. Stalagmites are similar formations, but they build up when the water hits the floor.

Cueva del Caballito de Mar (Seahorse Cave). This closeup version of the previous photo required the extreme telephoto setting of my camera. The cave gets its name from the stalactite in the center, which does indeed look like a seahorse. A number of other stalactites are also visible under the cave's ceiling. Fossils of sea creatures can be found all along Sumidero's walls. These were deposited when the area was under an ancient sea. Billions of tiny creatures died over the millennia and their calcified remains drifted to the sea bottom. Over time these became the thousand-foot limestone cliffs.

A small flock of black vultures suns themselves on a bit of beach. I was relieved to see that these fellows didn't seem to be feeding on the remains of any stranded tourist boat occupants. Black Vultures have a huge range, from the southeastern US to central Chile. This vulture has a 1.5 m (5 ft) wingspan and its plumage is black with a grayish-black head. It primarily feeds on carrion but includes eggs and newborn animals in its diet. The Black Vulture uses its excellent eyesight or keen sense of smell to find food. Vulture images have been found in the ancient Maya codices.

In some places, the canyon walls drop vertically into the water. This tended to magnify the effect created by the soaring walls above us. Previous to the construction of the Chicoasén Dam, the canyon was even deeper. In the area in front of the dam, the bottom is approximately 260 m (860 ft) below the water's surface.

At other places, erosion has created sloping walls that can sustain forest life. The Cañon del Sumidero cuts through a high plateau with the gorge running roughly south to north. It has created a natural boundary between the western side of the plateau (called Meseta de las Animas) and the eastern side (called Meseta de Ixtapa). You can see the rim of the Meseta de Ixtapa in the photo above. The canyon also forms the historical boundary between the territories of the Zoque people and the Maya.

Tropical rain forest lines some the shore and lower slopes of the canyon walls. The climate in the canyon area varies from hot and dry, to semi-hot and humid, to hot and humid. Temperatures range from the January cool season of 29C - 17C (84F - 63F) to the April hot season of 35C - 20C (95F - 69F). This, along with regular rain, creates a wide variety of both plant and animal life. The forests range from deciduous to pine and oak, depending on the altitude of the park.

Brown Pelicans roost in the tropical forest along the shore. The trees were full of them and they often launched themselves with a great flapping of wings as we passed close by. Due to hunting, logging, and other human intrusions, many of the animals in the park are endangered, including river crocodiles, spider monkeys, and ocelots. The biggest environmental problem faced by the park is trash, most of it generated by upstream municipalidades. A massive cleanup of the river removes more than 5000 tons of trash annually. Mexico's environmental agency has refused to act, claiming the responsibility belongs to the municipalidades. However, they are mostly poor and lack the resources to deal with the trash. When we visited, the cleanup must have been recently completed because we saw little or no garbage. 

Pausing for a break before entering another narrow stretch. Periodically, the boat captains paused, letting their craft drift with the current so that shutterbugs like me could get our fill of photos. A tour boat moving at cruising speed down the river can create large waves that violently rock other boats. This usually happens at a moment when stability is critical such as when setting up a delicate shot of wildlife, or a long-range photo of some interesting cliff feature. Still, I managed.

El Salto del Arbol de Navidad

El Arbol de Navidad (Christmas Tree Falls) was created by the same process as the stalactites. Near the top of the photo, water shoots out of a spring and drops vertically down, finally splashing on the slope below. Where it hits, and then cascades further down, minerals have been deposited. These create  scoop-like outcrops, giving the appearance of a spreading Christmas Tree. Hence, the name. The tour boats at the bottom give a sense of scale. The falls, high on the cliff, are still a hundred feet or more below the Meseta de Ixtapa.

By using maximum telephoto, I was able to capture a closeup of the spring. Notice how the water turns to mist in the open air a few feet below the spring's mouth. The mist drifts down until it finally strikes the outcrops below, where it re-liquifies.

Looking directly up the falls, you can see the spring and the Christmas Tree outcrops. It must have taken millennia for the tiny mineral particles to settle and accumulate, finally forming the scoop-like shapes you see above. The telephoto effect has created a compression where the distance from the outcrops to the spring seems far less than it actually is.

Water delicately drips and flows from one set mineralized outcrops to another. The moisture has drawn moss and other water loving plants to the surfaces and edges of the outcrops.

Flowing from the smaller "branches" to the larger, the water finally reaches the river. This side view shows the lovely shapes and colors that have been created by the action of the water. 

The tour boat captains couldn't resist making a run under the shower. Fortunately, I could see it happening with other boats so I had time to protect my camera before passing under the deluge. It had been a warm day and the spray was welcome, as long as my gear was safely tucked away. I got so many wonderful photos of Cañon del Sumidero, and there were so many additional spectacles, that I decided to make this a two-part "mini-series" within the over all Chiapas series. Next week, we'll continue through the canyon to visit the Cave of Colors, the riverbanks full of huge crocodiles, the Eco-Park, and then finish at the Chicoasén Dam. Stay tuned!

This completes part 14a of my Chiapas series. As always, I welcome feedback, corrections, and comments. If you would like to do so, please use the Comments section below or email me directly.

If you leave a question in the Comments section, PLEASE leave your email address so I can respond.

Hasta luego, Jim


  1. Wow, Jim! Thanks for bringing such stupendous, but little known wonders to light.

  2. Excellent article on the ruins of Tonina,


If your comment involves a question, please leave your email address so I can answer you. Thanks, Jim