There is one refugio and various, mostly free campgrounds. Most get crowded, which means sites can become unreasonably messy. Do your part to take your trash out of the park and follow a leave-no-trace ethic.
There is plenty of availability for camping at wild sites. Camping Ensenada is 16km from the park entrance and nearest the Senda Costera trail; Camping Río Pipo is 6km from the entrance and easily accessed by either the road to Cañadon del Toro or the Senda Pampa Alta trail. Camping Laguna Verde and Camping Los Cauquenes are on the islands in Río Lapataia. There are no amenities at any of the sites; contact the park visitor center, Centro de Visitantes Alakush, for more information.
The park has closed the fee-based campground at Lago Roca but is planning a new campground with showers in a yet-to-be-determined location.