The pristine park offers a chance to wander through peat bogs, stumble upon hidden lakes, trek through native canelo, lenga, and wild cherry forests, and experience the wonders of wind-whipped Tierra del Fuego's rich flora and fauna. Everywhere, lichens line the trunks of the ubiquitous lenga trees, and "chinese lantern" parasites hang from the branches.
Everywhere, too, you'll see the results of government folly, castoreros (beaver dams) and lodges.
Fifty beaver couples were first brought in from Canada in 1948 so that they would breed and create a fur industry. In the years since, without any predators, the beaver population has exploded to plague proportions (more than 100,000) and now represents a major threat to the forests, as the dams flood the roots of the trees; you can see their effects on parched dead trees on the lake's edge. Believe it or not, the government used to pay hunters a bounty for each beaver they killed (they had to show a tail and head as proof). To make matters worse, the government, after creating the beaver problem, introduced weasels to kill the beavers, but the weasels killed birds instead; they then introduced foxes to kill the beavers and weasels, but they also killed the birds. With eradication efforts failing, some tour operators have accepted them as a permanent presence and now offer beaver-viewing trips.
Visits to the park, which is tucked up against the Chilean border, are commonly arranged through tour companies. Trips range from bus tours to horseback riding to more adventurous excursions, such as canoe trips across Lapataia Bay. Entrance to the park is about $17USD.
Several private bus companies travel through the park making several stops; you can get off the bus, explore the park, and then wait for the next bus to come by or trek to the next stop (the service only operates in summer; check providers with the tourism office). Another option is to drive to the park on R3 (take it until it ends and you see the famous sign indicating the end of the Pan-American Highway, which starts 17,848 km [11,065 miles] away in Alaska, and ends here). If you don't have a car, you can also hire a private remis to spend a few hours driving through the park, including the Pan-American terminus, and perhaps combining the excursion with the Tren del Fin del Mundo. Trail and camping information is available at the park-entrance ranger station or at the Ushuaia tourist office. At the park entrance is a gleaming restaurant and teahouse set amid the hills, Patagonia Mia (Ruta 3, Entrada Parque Nacional www.patagoniamia.com); it's a great place to stop for tea or coffee, or a full meal of roast lamb or Fuegian seafood. A nice excursion in the park is by boat from lovely Bahía Ensenada to Isla Redonda, a wildlife refuge where you can follow a footpath to the western side and see a wonderful view of the Canal Beagle. This is included on some of the day tours; it's harder to arrange on your own, but you can contact the tourist office to try. While on Isla Redonda you can send a postcard and get your passport stamped at the world's southernmost post office. You can also see the Ensenada bay and island (from afar) from a point on the shore that is reachable by car.
Other highlights of the park include the spectacular mountain-ringed lake, Lago Roca, as well as Laguna Verde, a lagoon whose green color comes from algae at its bottom. Much of the park is closed from roughly June through September, when the descent to Bahía Ensenada is blocked by up to 6 feet of snow. Even in May and October, chains for your car are a good idea. No hotels are within the park—the only one burned down in the 1980s, and you can see its carcass as you drive by—but there are three simple camping areas around Lago Roca. Tours to the park are run by All Patagonia (Juana Fadul 58 2901/433–622; wwww.allpatagonia.com).