Río Sarmiento is a river channel within the Tigre Delta, located in the Province of Buenos Aires. As part of the delta's island system, there is no road access to the river; all access is exclusively by boat from the town of Tigre. Paddlers typically reach Tigre by train from Buenos Aires, then transfer to one of the available boat services — collective lanchas (shared boats) offer a more economical option, while private taxi boats provide faster, on-demand transport. Planning the return trip in advance is advisable, as boat services operate on schedules that may not always align with departure times.

The river supports kayaking and canoeing, and at least one established facility, Delta en kayak, operates directly on the Río Sarmiento. This operator offers kayak and canoe rentals, introductory lessons, guided tours, and motorized canoe excursions for groups. Equipment is provided. Programs run on Saturdays, Sundays, and holidays, with trips organized year-round for groups, schools, and corporate events. Night paddling tours are also available, combining on-water time with dinner at the riverside facility. The facility includes a sandy beach on the riverbank, a terrace overlooking the water, and a dock.

Isla Los Enanos, located at Río Sarmiento al 10, is a destination along the river offering water activities and overnight cabin rentals. Some areas of the delta, such as Tres Bocas, allow for walking on land, though movement through the delta generally depends on water transport. The sun reflecting off the water can be intense, making sun protection practical for any time on the water.