Río Pilcomayo National Park

Location: 224 mi (360 km) North of Resistancia, Formosa Province   Map

Area: 47,754 ha (118,000 acres)

Info: Ave Pueyrredón & RN 86, Laguna Blanca

Tel. (03718) 470 045

Open: daily

 

Río Pilcomayo National Park is located 224 mi (360 km) North of Resistancia, Formosa Province in Argentina. Río Pilcomayo National Park covers an area of 47,754 ha (118,000 acres). Río Pilcomayo National Park was found on September 29, 1951 to protect river Pulcomayo and surrounding marshes, creeks, lakes, rain forests and plains. It is situated in the North East part of Formosa Province of Argentina on the border with Paraguay. Río Pilcomayo National Park climate is subtropical. It recieves 1200 mm (47 in) of rain annually, although most of percipitations falls during the wet months of the ear. During summer months (December through February) temperatues can reach 104 degrees F, while in winter (June- August) temperatures can plummet to 30's degrees.
 
Keep in mind that much of Río Pilcomayo National Park is covered by wetlands, area inhabited by many dangerous animals. Treat any body of water with caution. Some of these animals include two caiman crocodile species, including the yacare caiman and the broad snouted caiman. Additionally protected bio reserve is inhabited by several species of constricting snakes that includes the yellow anaconda (Eunectes notaeus) and Hydrodynastes gigas.

 

Visiting tips

Best Time to Visit
The park can be visited any time, but the best period is April to October. Winter (June–August) is ideal for hiking and birdwatching because temperatures are milder and conditions are drier. Summer (November–March) brings extreme heat (often exceeding 40 °C) and heavy rains that can make dirt access roads impassable for days. Always check the weather and road status beforehand via the National Meteorological Service and park contacts. Annual rainfall is about 1,200 mm, concentrated in the warmer months; mean temperature is around 23 °C.

Getting There
By car from Formosa city: Roughly 130–175 km depending on the route (via RN 11 to Clorinda then RN 86, or RP 2). Portal Estero Poí is about 6 km from Laguna Blanca; Portal Laguna Blanca is roughly 10 km from Laguna Naineck on a gravel road.
From Asunción, Paraguay: Cross the San Ignacio de Loyola bridge, then take RN 86 from Clorinda (about 45–60 km to the portals).
Public transport: Buses reach Formosa or Clorinda; companies such as Godoy, Norte Bis, and Flecha Bus connect to Laguna Blanca or Laguna Naineck. From the towns, take a taxi, remis, or bike the final short distance. Buses do not enter the park itself.
Airports: Formosa’s El Pucú (FMA) or Asunción’s Silvio Pettirossi (ASU).

Fuel is available in Laguna Blanca and Laguna Naineck. Always confirm road conditions after rain—the Estero Poí access can become impassable, and Laguna Blanca access can have rough sections.

The Two Main Areas
Estero Poí offers a more wild experience of the characteristic palm savannas, termite mounds, and monte islets. It has an information office, a small self-guided trail, camping, and the start of the 16 km Lata Cue vehicle/bike trail that reaches a viewpoint (mangrullo) on the Pilcomayo River. There is also a bird observatory at Estero Pirity (covered structure reached by a short boardwalk and stairs) and trails such as Karaguatá Guatahá that lead to a lookout over Estero Catalina.
Laguna Blanca centers on a 700-hectare lagoon of scenic and cultural importance to the Qom people. Boardwalks (including a roughly 560 m low-difficulty section) allow easy access for viewing yacarés (caimans), capybaras, and aquatic birds, plus excellent sunsets. There is a visitor center, interpretive trails, a native plant nursery, and camping. Non-motorized boats (kayaks, canoes, or larger rabaska-style canoes) are allowed if previously disinfected (to prevent invasive species such as the golden mussel) and registered with rangers.

Activities
Birdwatching: One of the top draws, with 324–332 recorded species, including threatened or restricted-range birds such as the greater rhea, black-winged nightjar, black woodpecker, and strange-tailed tyrant, plus many waterbirds (storks, herons, jabiru, etc.). Bring binoculars and a field guide. The Estero Pirity observatory is especially useful.
Hiking: Multiple low-difficulty, interpretive, mostly accessible-with-assistance trails (Los Secretos del Monte, Hormiguero Gigante, Karaguatá Guatahá, Laguna Blanca boardwalks). Stay on marked paths.
Vehicle or bicycle circuit: The 16 km Lata Cue trail through palm savannas and monte islets to the river viewpoint (also bikeable). Drive slowly and only on designated routes.
Non-motorized boating: On Laguna Blanca (registration and disinfection required). Local providers sometimes offer kayak, canoe, or rabaska outings.
Camping and day use: Free camping zones at both portals with fire pits/parrillas, tables, toilets (including accessible ones), showers (hot water in some), electricity, lighting, and Wi-Fi in the service areas. Park water is treated but not potable—bring your own drinking water. Day-use hours follow daylight (roughly 8–18 h in winter season May 1–Sep 21; 7–19 h in the rest of the year); camping areas remain accessible 24 hours, but notify staff if entering/exiting outside regular hours.

Wildlife and Nature Highlights
Expect a mosaic of habitats supporting high biodiversity: roughly 85 mammal species, 42 reptiles, 32+ amphibians, 40+ fish, and the large bird list. Notable mammals include giant anteater, maned wolf (aguará guazú), tapir, howler monkeys, Azara’s night monkey (mirikiná—unique in Argentine parks), capybaras, collared and white-lipped peccaries, ocelot, puma, and river otter. Reptiles feature two species of yacaré and the yellow anaconda (boa curiyú). There have been jaguar (yaguareté) records, including camera-trap photos. Do not feed fish—piranhas are present.
Characteristic flora includes caranday palms (Copernicia alba) dominating the savannas, hard-wood trees (lapacho, quebracho colorado chaqueño, algarrobo, guayacán) in the monte islets, and floating/emergent wetland plants such as camalotes, pirí, and huajó.

Essential Practical Tips
Water: Carry at least 2 liters per person per day. Park water is not for drinking.
Insects and sun: Mosquitoes and other insects are abundant—bring strong, long-lasting repellent. Use sunscreen, a hat, light-colored lightweight clothing (long sleeves/pants recommended), and sunglasses. Light non-slip footwear is useful on potentially muddy or slippery ground.
Other gear: Food and snacks, trash bags (pack out what you pack in), basic first-aid kit, binoculars/camera, and extra fuel. A bird guide enhances the experience. Check your vehicle before leaving town.
Registration and rangers: Register on arrival and consult park rangers. They provide current trail and access information.
Rules: No hunting, fishing, plant collecting, or disturbing wildlife. Stay on marked trails and roads. Fire only in designated spots (clear vegetation around the fire and fully extinguish with water). No pets. Drive slowly. Do not litter (glass, plastic, or cans can start fires).
Road and weather caution: After heavy rain, accesses can close or become difficult for up to 72 hours. Contact the park in advance.
Duration: One full day is feasible for the main highlights; two days allow more thorough exploration of both portals and trails.

Accommodation and Nearby Services
Free camping is available inside both recreational areas (register in advance for safety). In Laguna Blanca there are modest hotels (examples include Hotel Guaraní, Hotel Brimalú, and Hotel Imperial). Simple lodging and basic services (shops, fuel) exist in both Laguna Blanca and Laguna Naineck. Laguna Blanca hosts the National Pomelo Festival. Farther afield is the large Bañado La Estrella wetland system (excellent for birds) and Formosa Natural Reserve.

Contacts
Email: riopilcomayo@apn.gob.ar
Phone: +54 3718 470045
Official site: argentina.gob.ar (search Parque Nacional Río Pilcomayo) — also check Facebook and Instagram for updates
Intendencia is near Laguna Blanca (Pueyrredón and RN 86)

 

Geography

Topography and Geology
The park occupies a vast, gently sloping plain with minimal elevation variation (generally sloping slightly from west to east). Subtle differences in height of just a few meters create major environmental contrasts, especially during floods.
Geologically, it is a sedimentary basin formed when a depression in Paleozoic crystalline rocks filled with organic and inorganic sediments. The uppermost layers are of fluvial and aeolian origin. Eastern soils tend toward silts and clays (less permeable), while western soils are coarser and more porous. Faults linked to Andean uplift run roughly parallel to the Paraguay River.

Hydrography and Wetland Character
The Pilcomayo River (Río Pilcomayo) forms the park’s northern boundary and is its defining watercourse. This major river (about 1,590 km long, originating in the Bolivian Andes and eventually joining the Paraguay River) carries heavy sediment loads and drives the region’s hydrology. In its lower course it is highly dynamic, with shifting channels, overflow, and seasonal flooding.
During the wet season the river and local rainfall inundate low areas, creating interconnected temporary lakes, channels, esteros (marshes), bañados (seasonally flooded grasslands), and permanent freshwater marshes. These alternate with drier periods, producing strong wet-dry cycles that shape the entire landscape. Most surface water bodies are temporary, but the southern part of the park holds the larger, more permanent Laguna Blanca (~700–800 ha), a key habitat for waterbirds, caimans, and other wildlife.
The overall wetland complex consists of rivers, lagoons, permanent and seasonal marshes, and flooded grasslands interspersed with gallery (riparian) forests. This mosaic is what earned the site Ramsar status.

Climate
The climate is subtropical humid (sometimes described as tropical humid with a marked winter decrease in rainfall rather than a true dry season). Mean annual temperature is about 23 °C and mean annual precipitation is roughly 1,200 mm, with peaks typically in March and November and lower totals in winter. Summers are hot, with maxima frequently exceeding 40 °C (and occasionally higher); winters are mild but can bring occasional frosts. The region also experiences frequent tornadoes.

Landscape Mosaic and Vegetation Zones
Small elevation differences produce four main environmental types:

Savannas / palm savannas — Extensive grasslands dotted with caranday (white palm / Copernicia alba) palms (up to ~14 m tall with glaucous green fan leaves). These dominate much of the park and support termite mounds, maned wolves, rheas, and other grassland species.
Wetlands — Low-lying bañados, esteros, and lagoons with aquatic and floating vegetation (water hyacinths and others). Laguna Blanca is the standout permanent water body.
Isletas de monte (forest islands) — Patches of denser woodland on slightly higher ground, featuring quebrachos (Schinopsis balansae and Aspidosperma quebracho-blanco), lapachos, algarrobos, and other Chaco trees.
Selva de ribera / gallery forests — Narrow belts of riparian forest along the Pilcomayo and its former channels, with figs, other trees, lianas, vines, and epiphytes, subject to periodic extraordinary floods.

Most of the park’s surface is covered by grasslands and caranday palm groves, with wetlands in the depressions and forest islands on the higher points. This water-driven mosaic is characteristic of the Humid Chaco.