One of the most pristine areas of Peru’s northern Amazon is the Reserva Nacional Pacaya-Samiria, an immense wedge of flooded rainforest between the Ucayali and Marañon Rivers. At just over two million hectares, it is Peru’s largest nature reserve, and its vast network of lakes, lagoons, swamps, and wetlands harbor many endangered animals. Opportunities for spotting wildlife here rival Parque Nacional Manu, though there are no lodges in the reserve.

Commonly seen animals in the reserve include the huge charapa turtle, the Amazon manatee, tapir, gray and pink river dolphin, black and white caiman, giant otter, twelve types of monkeys, the monstruous paiche fish, and hundreds of aquatic birds. The best times to visit the park are the low-water months July–December, when animals can often be spotted on the riverbanks.

The Reserva Nacional Pacaya-Samiria began in the 1940s in an effort to save the endangered paiche. After biologists realized its world-class biodiversity, the present reserve was established in 1982. The reserve includes a large number of colonists and indigenous inhabitants—more than 30,000 at last count, including Cocamas, Huitotos, Boras, and Yaguas Indians.

Visitors to Reserva Nacional Pacaya-Samiria require a guide, a US$33 entrance fee, and at least five days, whether you motor the 300 km upriver from Iquitos (15–18 hours) or downriver from Yurimaguas (10 hours). Because there are no lodges in the reserve itself, options range from deluxe cruises to rustic camping trips, though a few native lodges have recently opened.

Trips usually travel up the Río Ucayali to the town of Requena, and then enter the heart of the reserve through the Canal de Puinahua and the Río Pacaya. Generally speaking this southern side of the reserve has more wildlife than the northern area along the Río Samiria.

A fast access point for the reserve is Yurimaguas, which lies six hours on rough road from Tarapoto. The cargo boats that leave here most afternoons chug down the northern border of the park for nearly two days. The fringes of the park, however, have been heavily impacted by colonists, and the more pristine areas can now only be reached by a two- to three-day canoe journey inside the reserve.

Sometime in the middle of the first night after leaving Yurimaguas, cargo boats stop in the small village of Lagunas. From here it is possible to contract a local guide and a canoe for about US$20 per day, though there are no guarantees on the quality of service.

A surer bet is to set up a guide and transport in Tarapoto through either Puerto Palmeras (Carretera Marginal Sur Km 3, tel. 042/52-3978, cta [at] puertopalmeras [dot] com, www.puertopalmeras.com) or adventure guide César Reategui (Lamas 261, tel. 042/52-3899, lapatarashca [at] hotmail [dot] com, www.lapatarashca.com).

From Lagunas, a half-hour motocar ride will take you to the headwaters of the Río Samiria. From here, it is a three-day paddle to Laguna Pastacocha, a huge oxbow lake teeming with wildlife. Fewer tourists enter the park via this route, so this is more of a wilderness experience. The farther you go, the more you are likely to see.

Agencies from either destination usually take care of the official permission that is required from the natural resources authority INRENA in Iquitos (Pevas 350, tel. 065/23-1230) or in Lima (Los Petirrojos 355, Urb. El Palomar, tel. 01/224-3298). If you are going with an independent guide, inquire about this paperwork beforehand.

Camping and canoeing through the Reserva Nacional Pacaya-Samiria is an amazing experience with the right equipment and a good operator. When combined with a stay at a community-based lodge, it is one of the best ways to understand the rhythms of life in a flooded forest.