Sumidero Canyon (Spanish: Cañón del Sumidero) is a deep natural canyon located just north of the city of Chiapa de Corzo in the state of Chiapas, in southern Mexico. The canyon began forming around the same time as the Grand Canyon in Arizona, U.S., due to a crack in the Earth's crust and later erosion caused by the Grijalva River, which still flows through it. The canyon has tall walls that reach up to 1,000 meters (3,300 feet) high. Along its 13-kilometer (8-mile) length, the river turns as much as 90 degrees through the narrow passage.
The canyon is surrounded by the Sumidero Canyon National Park, a protected natural area in Mexico that covers 21,789 hectares (53,840 acres) across four municipalities in Chiapas. This park is managed by the National Commission of Protected Natural Areas (CONANP). Most of the park’s vegetation includes low- to medium-height deciduous rainforest, with smaller areas of mixed pine-oak forest and grassland. At the northern end of the canyon lies the Chicoasén Dam and its artificial reservoir, one of several dams on the Grijalva River. These dams are important for storing water and producing hydroelectric power in the region.
Sumidero Canyon and the national park are the second most important tourist attraction in Chiapas. Most visitors are Mexican tourists who view the canyon from boats that depart from Chiapa de Corzo along the river. The park is near Tuxtla Gutiérrez, the largest city in the state, which has led to human encroachment and settlement on park land. Additionally, urban areas and logging industries upstream from the canyon have caused serious pollution. Up to 5,000 tons of solid waste are removed from the Grijalva River each year. This waste accumulates in the canyon because of its narrow shape, the way water flows converge, and the presence of the Chicoasén Dam.
Description
The Sumidero Canyon was created by cracks in the Earth's crust and erosion from the Grijalva River, which still flows through it. Its formation began about 35 million years ago, making it the same age as the Grand Canyon on the Colorado River. The Grijalva River is the main water system in the area, starting in the Cuchumatanes region of neighboring Guatemala. It flows through Chiapas, including a 13-kilometer section of the canyon from south to north, then continues to Tabasco before joining the Usumacinta River. This river basin is one of the two most important in Chiapas and one of the most important in Mexico. It has a total length of about 766 kilometers (476 miles) and drains an area of 7,940 square kilometers (3,070 square miles), with an average water flow of about 40 million cubic meters.
In addition to the Grijalva River, there are other water sources in the area, including seasonal streams, some of which form waterfalls on the canyon’s sides, and underground water that created caves and karst formations. The last major water feature in the area is the manmade Chicoasén Dam reservoir.
The canyon is deep and narrow, with vertical walls. It changes direction up to 90 degrees in some places, separating the Meseta de las Animas mesa in the west from the Meseta de Ixtapa mesa in the east. The canyon’s width ranges from 1 to 2 kilometers (3,300 to 6,600 feet). Most walls are between 200 and 700 meters (660 and 2,300 feet) high, reaching up to 1,000 meters (3,300 feet) at their highest point. These walls show layers of limestone from the Upper Mesozoic period, which contain fossils of sea creatures. During the Mesocretac Period, rising ocean floors helped form many of the area’s mountains.
Inside the canyon, there are 30 rapids, 5 waterfalls, 3 beaches, 2 freshwater springs, and a cofferdam 3 meters wide. The canyon is home to endangered and threatened species, such as the Central American river turtle and the American crocodile, which live near the river. The canyon’s walls have many small caves, rock formations, and other features. The most famous cave is the Cueva de Colores, or “Cave of Colors,” named for the pinkish colors on its walls caused by minerals like magnesium and potassium. Inside the cave is an image of the Virgin of Guadalupe, often surrounded by flowers and candles left by visitors. Another cave, called the Cueva de Silencio, or “Cave of Silence,” has no echoes or sounds inside. In another small cave, there is a stalactite shaped like a seahorse, called the Caballito de Mar. The most famous seasonal waterfall is the Árbol de Navidad, or “Christmas Tree,” where moss covers deposits from the waterfall. During the rainy season, water and light change the colors of the “branches,” making the formation stand out. The park was considered for the Seven New Natural Wonders of the World in 2009.
Although the park has rich biological, ecological, and cultural diversity, few studies have been done in the area. This lack of research means there is not enough information about species, habitats, or water flow. There is also limited knowledge about how human activities affect the park.
The park is located in the Central Valley of Chiapas and borders the Northern Mountains region. Altitudes range from about 600 meters (2,000 feet) in the Chiapa de Corzo municipality to 1,200 meters (3,900 feet) at the El Roblar lookout point. This geography creates air flow from northwest to southeast and three main climates: hot and dry (where airflow is blocked), semi-hot and humid, and hot and humid. The park receives about 1,000 mm of rain during the rainy season (May to October) and 200 mm during the dry season (November to April). The average yearly temperature is 26°C. The rugged terrain also creates many microclimates.
Most of the park’s vegetation, especially near the canyon, is dense tropical rainforest. Many plant species belong to the Fabaceae family (59 species) and the Asteraceae family (25 species), which are common in the region. Other important families include Orchidaceae and Euphorbiaceae (22 species each), Convolvulaceae (17 species), and Cactaceae (11 species). About 122 plant species are valuable for ornamental use, with 46 having medicinal uses and 31 useful for logging. These plants mostly grow in rainforest areas. Rainforest vegetation is mostly deciduous, losing leaves during the dry season, but some areas have evergreen forests, pine and oak forests, grasslands, and secondary vegetation.
The three main vegetation types are low-height rainforest, medium-height rainforest, pine-oak forest, and meadows. Medium-height deciduous rainforest is found on both sides of the canyon, in the north and east near San Fernando and in the Cañada Muñiz area, at altitudes between 150 and 1,250 meters above sea level. These forests grow on basalt or granite rock with lime deposits, covering 11,382 hectares (28,130 acres). Many trees lose leaves in the dry season, but some remain green year-round. Trees in these areas range from 25 to 30 meters tall, and the dense tree cover lowers ground temperatures during the rainy season. Common tree species include breadnut, guanacaste, totoposte, jocotillo, cedar, cuaulote blanco, hormiguillo, chicozapote, tempisque, and various amate fig trees. Under the canopy, there is a lot of plant diversity, including palms, araceas, epiphytes (air plants), orchids, bromeliads, and cacti. Cacti are mostly found on the canyon’s vertical walls and belong to the Acanthocereus family. In the 1970s, 3,818 hectares (9,430 acres) of forest were in good condition, or 17.72% of the total land area. By 1993, this had dropped to 1,107 hectares (2,740 acres), or 5.35%. From 1990 to 2000, it is
National park
The Sumidero Canyon National Park was created by a law passed in 1972 by the state of Chiapas. This law made the area around the canyon a protected area to preserve its geology, history, and wildlife, and to allow scientists to study it. In 1980, the national government took control of the park and expanded it to cover 21,789 hectares. Most landowners in the area were paid for their land, but not all people or businesses were removed. Since then, the park has been managed by several agencies, including SAHOP, SEDUE, and SEMARNAP. Today, the Comisión Nacional de Áreas Naturales Protegidas and the Secretaría de Educación Pública are the main managers. In 2004, the park was added to a special list called the Ramsar Convention because of its important ecosystems and water systems. In 2000, the park was also named a Región Prioritaria Terrestre and an Área de Importancia para la Conservación de las Aves by the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO). Between 2005 and 2006, this agency expanded the park again by taking over land in the municipalities of San Fernando and Tuxtla Gutiérrez, adding 1,660 hectares. Despite these expansions, the park is still smaller than most other national parks in Mexico.
The center of the park is the Sumidero Canyon and the Grijalva River, which flows from south to north through the canyon. The park’s borders along the river are marked by the Belisario Domínguez Bridge, where the Pan-American Highway crosses, in the south, and the Chicoasén Dam, 35 kilometers to the north. The rest of the park’s borders include parts of the municipalities of Tuxtla Gutiérrez, Chiapa de Corzo, Osumacinta, and San Fernando. This area is mostly located in the Central Valley region of Chiapas. The park is open every day of the year. It is divided into four sections: the northwest includes medium-height, somewhat deciduous rainforest and some lowland rainforest and grassland in the municipalities of Osumacinta and San Fernando; the western section has similar vegetation and is entirely in San Fernando; the eastern section has pine forests and medium-height semi-deciduous rainforest and grasslands in Chiapa de Corzo; and the southeast includes most of the canyon’s sides and a navigable part of the Grijalva River, but only small amounts of medium-height rainforest and pachycaulous vegetation. The main way to reach the park by land is from Tuxtla Gutiérrez north through Osumacinta and past the Chicoasén Dam. Another access point is from Chiapa de Corzo by boat from the Cahuaré Docks. Since the canyon is the main attraction, several viewpoints have been built along the canyon’s edge. La Ceiba is the closest to Tuxtla Gutiérrez, only eight kilometers away. The Los Chiapas viewpoint is near the part of the canyon where the walls rise highest above the river. According to legend, some Chiapa people chose to jump from this spot rather than submit to Spanish rule. This viewpoint also has a restaurant.
Conservation issues
The most important problem for the park is pollution in the Grijalva River, which flows through the Sumidero Canyon. Other problems include human activity and illegal settlements. About 1,500 to 2,000 hectares, or about 6% of the park, have been taken over by illegal homes near the city of Tuxtla Gutiérrez since the park was created. It is estimated that about 15,000 people live inside the park’s borders. Most of these homes belong to poor people who moved to the city from other areas. The need for housing has led to the creation of illegal subdivisions that are sold without proper ownership papers. Three main neighborhoods that developed this way are Patria Nueva Alta, Arroyo Blanco, La Esperanza, and Las Granjas. This expansion is because of the fast population growth in Tuxtla Gutiérrez and Chiapa de Corzo. This growth has caused land disputes, loss of natural habitats, and deforestation. In 2002, the federal and state governments signed an agreement to remove illegal settlements and stop further expansion. Eviction operations, like one in 2005 that removed about 100 people, have been carried out. However, because illegal settlements have caused so much damage, a 2007 report said the only option is to relax rules for part of the park to stop more expansion. Disputes over the park’s boundaries, as defined in 1980, have made the situation worse. Since 2009, park officials have tried to stop illegal settlements. Despite these efforts, some areas of the park remain well-preserved because the land is very rugged.
In addition to illegal homes, there are legal settlements and activities that affect the park. Eight ejidos (communities that own land collectively) border the park and impact it: San Antonio Zaragoza, Venustiano Carranza, Francisco Sarabia, Gabriel Esquinca, Benito Juárez, Osumacinta, El Palmar, 16 de Septiembre, and Nuevo Bochil. Five ejidos and three settlements are inside the park: Libertad Campesina (495 people), Nueva Esperanza (139), La Unión (329), El Paraíso (134), Tierra Colorada (199), and La Candelaria / Triunfo Agrarista (631). In 2005, the total population inside the park was 1,927. Human activity makes this park especially vulnerable to wildfires, and it was the most damaged by wildfires in Mexico from 2009 to 2011. Many fires started near the park, such as one on a nearby farm in May 2011.
Lime and other mining operations also exist inside the park. These operations are legal because they started before the park was created. However, they have destroyed about 2,600 hectares. Mining causes noise, smoke, dust, and small tremors from explosions. Environmental damage comes from mining waste that flows into the Grijalva River. Dust and smoke have also created a white coating on nearby plants.
Wastewater from about 552,000 people in seventeen nearby towns flows into the Grijalva River through the canyon, as reported by park director Edda González del Castilla. Most of this waste comes from Tuxtla Gutiérrez, Chiapa de Corzo, Berriozábal, and Chicoasén. Much of the sewage enters the Grijalva through the Sabinal River, which carries most of Tuxtla Gutiérrez’s wastewater. Trash and raw sewage also enter the river from smaller streams. Agricultural waste comes from farms along the river and its tributaries.
The most visible pollution is garbage, especially plastic containers, which mostly comes from homes and businesses in Chiapa de Corzo and Tuxtla Gutiérrez. This trash increases during the rainy season, when runoff carries more waste into the river. While plastic bottles are the most noticeable, other signs include overgrown water lilies (from high levels of waste) and dead animals. This accounts for about 5% of the total waste in the river each year. Between 80% and 90% of the solid waste in the river comes from branches, wood, rocks, sediment, and debris from logging, which causes deforestation. This waste enters the river during the rainy season, especially from the Villa Flores and Villa Corzo areas. Most of the waste is hidden under the water.
As waste flows through the Grijalva River, it is blocked by the narrow canyon and the Chicoasén Dam. This is especially true at a point called "El Tapón" (The Plug), where two water currents meet before the dam’s reservoir. It is estimated that about 5,000 tons of trash accumulate in the river each year, making it one of the five most polluted rivers in Mexico. In 2010 alone, 3,700 tons of waste were removed from the canyon area. Many fish have died or developed health problems due to pollution from fertilizers, pesticides, and other chemicals. This threatens native American crocodiles, as these chemicals poison the fish they eat. In May 2011, the Fédération Internationale de Natation canceled its annual swim marathon in the canyon because of pollution risks. The Comisión Nacional del Agua and the government of Chiapas disputed this, saying test results showed pollution levels were safe.
Efforts to clean the river happen year-round and during specific seasons. Daily work is done by workers from the Comisión Nacional de Áreas Naturales Protegidas (CONANP) and the Chiapas Tourism Secretariat, who remove 12 tons of garbage from the Grijalva River each day. Seasonal cleanups occur during the rainy season, especially in September and October. These efforts involve local police, civil protection agencies, social organizations, the army, and volunteers. Cleanups can include up to 600 people using 32 boats from tourist cooperatives. In 2005, more than 60,000 tons of trash were removed during a canyon cleanup campaign. About 40 tons of garbage is collected daily during these efforts.
While cleanup has improved conditions, trash accumulates again, especially during the rainy season. Some boat ride fees pay for cleanup, but operators say the canyon remains full of trash. CONANP says cleanup efforts are not enough. Mexico’s federal environmental agency, the Secretaría de Medio Ambiente y Recursos Naturales (Semarnat), says it cannot help because local governments are responsible for waste disposal. However, many local governments lack landfills or systems to separate recyclable materials.
Tourism
The canyon is a major tourist attraction in the state, offering opportunities for eco-tourism and extreme sports. The part of the Grijalva River that can be traveled through is mainly used to take visitors to the canyon area. The park has six lookout points that can be reached by land. These are called La Ceiba, La Coyota, El Roblar, Tepehuaje, Los Chiapas, and Manos. During the rainy season, waterfalls such as Árbol de Navidad, Cueva del Hombre, Cueva del Silencio, Cueva de Colón, Cueva de Colores, and Cueva del Suspiro attract more visitors. A less well-known attraction is the archaeological site called the Ruins of Berlin. The most important economic activity in the canyon is ecotourism. Most visitors are from Mexico, and weekends are the busiest times for activities like biking, swimming, hiking, camping, and picnicking.
The canyon is the second most visited site in Chiapas, after Palenque. The park is visited by about 300,000 people each year, with 80% of them from Mexico and the rest from other countries. During vacation times, the park may receive between 1,000 and 7,000 visitors daily. These visitors either arrive by car to reach the lookout points or by boat from Chiapa de Corzo. Entrance and boating fees help fund clean-up efforts, generating about 70,000 pesos per day. The number of visitors reached a peak in 2003, with about 196,500 people visiting the park.
Commercial activity in the park is limited to businesses that serve tourists, such as food sales and the sale of Mexican handcrafts and folk art. Tour operators work in cooperatives, and food and craft vendors operate independently. These merchants must receive an annual permit to operate within the park. The most important businesses are the boats that carry people through the canyon along the Grijalva River. Most of these boat tours begin in Chiapa de Corzo and travel about 30 kilometers (20 miles) to the Chicoasén Dam. Chiapa de Corzo has two main docks for this activity. The largest and oldest is called Cahuare, which has paved areas and a restaurant. The second dock also has restaurants and a swimming area. These two docks host six tour cooperatives with about 120 boats that can carry between 10 and 40 passengers each. As they travel through the canyon and to the dam, the boats provide information about the environment, history, and culture. These are the most organized tourist activities in the park.
A series of accidents involving these boats occurred from late 2009 to early 2010, resulting in six deaths and injuries to 62 others. The accidents happened on old, unsafe boats, many of which operated without permission and had underage or unlicensed crew members. There were no ambulance boats or first aid services on shore. Two cooperatives, Ángel Albino Corzo and Nandiume, were suspended and fined for the accidents, removing about 60 boats from operation. These accidents caused major problems for the tourism industry.
For visitors who choose to see the canyon from the lookout points above, there are restaurants, camping areas, and picnic spots.
Other attractions in the park include general ecotourism and extreme sports. The park has hiking trails, and sports fishing is allowed with a permit. Some areas offer rentals for kayaks and other boats. The Amikúu Ecological Park is located within the canyon area and can be reached by boat from Chiapa de Corzo. The park is divided into three sections: Discover the Canyon, Colors of Chiapas, and Area of Adventure. Discover the Canyon is near the dock area, where visitors can learn about the canyon’s history and watch a video about its geological formation. There is also a souvenir shop here. Inside the park, there is a 300-meter zip line. Colors of Chiapas is a small museum that displays traditional clothing and musical instruments of the state’s indigenous people. Area of Adventure includes a rainforest tour with a suspension bridge, a herpetarium, an aviary, and enclosures for jaguars and crocodiles. The park opened in 2009 with an initial cost of 120 million pesos.
Extreme sports include mountain biking, rappelling, spelunking, and others. Rappelling allows access to small caves that cannot be reached in other ways. The dam area has recreational fishing with an annual tournament. One major event is the Copa Mundo Fino swimming marathon. In 2006, an Australian base jumper died after jumping from an 800-meter cliff in the canyon during a sponsored event. The event included jumpers from Australia, the U.S., Europe, and Mexico.
Chicoasén Dam
At the northern end of the Sumidero Canyon is the Chicoasén Dam, also known as the Manuel M. Torres Dam. This dam is one of several built along the Grijalva River to store water and generate hydroelectric power. The dam and its reservoir are part of the Sumidero Canyon system. The Sumidero Canyon National Park is located along the Grijalva River, with the Chicoasén Dam marking the northern boundary and the Belisario Domínguez Bridge marking the southern boundary. The dam was built between 1974 and 1980. The reservoir covers about 2,193 hectares, and the dam complex employs approximately 600 workers.
The Chicoasén Dam helps control the flow of the Grijalva River, as well as the Hondo River and the Muñiz, El Jardín, and El Cacao streams, which come together to form the Osumacinta River. This reservoir is one of the most important in the country. The hydroelectric power station at the dam is also one of the most important in the country, with thirty generators that have an installed capacity of 3,928.48 megawatts. This amount of energy is just over thirty percent of all hydroelectric power produced in Mexico.
History and archaeology of the area
The history of the area is linked to the Chiapa people, who lived in the Central Valley before the Spanish arrived. Where the Chiapa people came from is unknown, but some ideas suggest they moved north from Nicaragua or Paraguay. Their main home was in Chiapa de Corzo, near the canyon, with a strong, protected area in the higher parts of the canyon to stay safe from attacks. The Chiapa people strongly fought against the Spanish and were not controlled until Diego de Mazariegos arrived in 1528. Their final place of safety was the fortified area, now called the archaeological site of the Ruins of Berlin. Here, the last Chiapa people stayed from 1528 to 1535 after the Spanish took over the main city. A story says that when this last strong place fell, the remaining Chiapa people died together by jumping into the canyon. Since then, the canyon has been a boundary between the Zoque and Tzotzil peoples.
Until the 20th century, the canyon was not well explored. In 1895, three French people tried to explore the canyon but drowned in the river. In 1932, an American also tried to explore the canyon but died there. These events led to stories about witchcraft in the area and the danger of the canyon’s crocodiles. In 1960, a group of Mexican soldiers, called the "red handkerchiefs," successfully traveled through the canyon by boat for more than twenty kilometers. This made the canyon more accessible for local people, leading to early tourism and the hunting of crocodiles and other animals.
There has been little research about the area’s past. The main site is called the Ruins of Berlin, named after German explorer Heinrich Berlin, who visited in 1946 and called the area "Sumidero." This site is located seven kilometers from the Belisario Domínguez Bridge in Tuxtla, near the edge of the river. It covers an area 467 meters long and 60 meters wide, with small hills surrounding open spaces. The site was first described in 1923 and 1932 by Becerra, who called it Chiapa Viejo and said it was the capital of the Chiapa people. However, in 1966, Remesal found it was not the main city but a smaller site. The last major study was in 1976 by Alejandro Martínez, who found 24 separate sites, nine of which are hills and fifteen are in caves. One of these caves has paintings showing the area was used by people as early as the very early Pre Classic period.