Created in 1975, PARQUE NACIONAL CORCOVADO protects an undeniably beautiful and biologically complex area of land, with deserted beaches, some laced with waterfalls, high canopy trees and better-than-average wildlife-spotting opportunities. Many people come with the sole purpose of spotting a margay, ocelot, tapir and other rarely seen animals. Of course, it’s all down to luck, but if you walk quietly and there aren’t too many other humans around, you should have a better chance of seeing some of these creatures here than elsewhere.
Serious walking in Corcovado is not for the faint-hearted. Quite apart from the distances and the terrain, hazards include insects (lots of them, especially in the rainy season: take a mosquito net, tons of repellent and all the precautions you can think of), herds of peccaries – who have been known to menace hikers – rivers full of crocodiles (and, in one case, sharks) and nasty snakes, including the terciopelo and bushmaster, which can attack without provocation. That said, most of these are present elsewhere in the country anyway, and everybody seems to make it through Corcovado just fine. But you must at least be prepared to get wet, dirty and incredibly hot – bear in mind that the sea does contain sharks, though everyone swims in it and no attacks have ever been recorded.
The terrain in Corcovado (literally “hunchback”) varies from beaches of packed or soft sand, riverways, mangroves and holillo (palm) swamps to dense forest, although most of it is at lowland elevations. Hikers can expect to spend most of their time on the beach trails that ring the outer perimeters of the peninsular section of the park. Inland, the broad, alluvial Corcovado plain contains the Corcovado Lagoon, and for the most part the cover constitutes the only sizeable chunk of tropical premontane wet forest (also called tropical humid forest) on the Pacific side of Central America. The Osa forest is as visually and biologically magnificent as any on the subcontinent: biologists often compare the tree heights and density here with that of the Amazon basin cover – practically the only place in the entire isthmus of which this can still be said.
The coastal areas of the peninsular section of the park receive at least 3800mm of rain a year, with precipitation rising to about 5000mm in the higher elevations of the interior. This intense wetness is ideal for the development of the intricate, densely matted cover associated with tropical wet forests; there’s also a dry season (Dec–March). The inland lowland areas, especially those around the lagoon, can be amazingly hot, even for those accustomed to tropical temperatures.
The park’s three longest trails all lead from the peripheral ranger stations to Sirena, where you can stay for a day or two in the simple lodge, exploring the local trails around the Río Sirena. Though there is some overlap in the type of flora and fauna you might see along the way on the different trails, each offers a distinct hiking experience. For this reason, and if your schedule permits, it’s a good idea to walk into Sirena on one trail and back out via another. If you plan to spend a few days in the park, consider hiking in from Los Patos, spend a night or two in Sirena and then back out to La Leona; it’s much easier to move on from La Leona at the end of a hike than from Los Patos.
The small hamlet of La Palma, 24km northwest of Puerto Jiménez, is the starting point for getting to the LOS PATOS ranger station. It’s a twelve-kilometre walk to the park, much of it through hot lowland terrain. A much more sensible idea, however – given the hike that awaits you in the park – is to try and arrange for a taxi in La Palma to take you as far as water levels on the bumpy dirt track will allow. You’ll want to start your hike from Los Patos to Sirena early, so plan on arriving at Los Patos soon after dawn or, preferably, the night before.
The well-marked twenty-kilometre inland trail from Los Patos to Sirena is, for many, the holy grail of Corcovado hikes. From Los Patos the trail takes you steeply uphill for some 5km into high, wet and dense rainforest, after which the rest of the walk is flat, but extremely hot. This is a trail for experienced rainforest hikers and hopeful mammal-spotters, giving you a reasonable chance of coming across, for example, tapirs, peccaries, margay or the tracks of tapirs and jaguars. That said, some hikers come away very disappointed, having not seen a thing. It’s a gruelling trek, especially with the hot inland temperatures (at least 26°C, with 100 percent humidity) and the lack of sea breezes, although there are crude shelters en route where you can rest in the shade (but not camp), but it is probably best avoided if you’ve not done much rainforest hiking before.
It’s a ninety-minute walk along the beach from the village of Carate to enter Corcovado at the LA LEONA ranger station: refreshments are available en route at the Corcovado or La Leona tent camps. Once at La Leona, a sixteen-kilometre trail runs to Sirena just inland from the beach, making it easy to keep your bearings. You can only walk its full length at low tide; if you do get stuck, the only thing to do is wait for the water to recede. If you can avoid problems with the tides, you should be able to do the walk in five to six hours, taking time to look out for birds. The walking can get a bit monotonous, but the beaches are uniformly lovely and deserted, and you may be lucky enough to spot a flock of scarlet macaws in the coastal trees – a rare sight. You will probably see (or hear) monkeys, too. Take lots of sunscreen, a big hat and at least five litres of water per person – the trail gets very hot, despite the sea breezes.
Hikers and tour groups coming from the Bahía Drake area enter the park at the SAN PEDRILLO ranger station, from where there are a few well-marked and short trails leading into the forest. The ranger station itself can be a good spot to see foraging wildlife, as there are several fruit trees within close proximity to it.
Corcovado’s most heroic walk, all 25km of it, is from San Pedrillo to Sirena, the stretch along which you’ll see the most impressive trees. It’s a two-day trek, so you need a tent, sleeping bag and mosquito net, and you mustn’t be worried by having to set up camp in the jungle. Fording the Río Sirena, just 1km before the Sirena ranger station, is the biggest obstacle: this is the deepest of all the rivers on the peninsula, with the strongest out-tow current, and has to be crossed with care, and at low tide only – sharks come in and out in search of food at high tide. Be sure to get the latest information from the San Pedrillo rangers before you set out.
The first half of the walk – a seven-hour stint – is in the jungle, just inland from the coast. Much of the rest of the hike is spent slogging it out on the beach, where the sand is more tightly packed than along the La Leona–Sirena stretch. Some hikers do the beach section of the walk well before dawn or after dark; there are fewer dangers (like snakes) at night on the beach and as long as you have a good torch with lots of batteries and/or the moon is out, this is a reasonable option.
EL TIGRE ranger station, at the eastern inland entrance to the park, is a decent place to take breakfast or lunch with the ranger(s) before setting off on the local trails. To get there from Jiménez, drive 10km north and take the second left, a dirt track, signed to El Tigre and Dos Brazos. The short walking trails laid out around the ranger station provide an introduction to Corcovado without making you slog it out on the marathon trails, and can easily be covered in a morning or afternoon.