Lac à l'Épaule is a natural freshwater lake located within Jacques-Cartier National Park (Parc de la Jacques-Cartier), in the unorganized territory of Lac-Jacques-Cartier, within the La Côte-de-Beaupré Regional County Municipality in the Capitale-Nationale administrative region of Quebec. It sits at an elevation of 651 metres above sea level and measures 2.9 kilometres in length and 0.8 kilometres in width, covering approximately 305 acres with roughly 5.23 miles of shoreline. The lake has a small bay on the east bank and is elongated in shape, set between surrounding mountains. The Rivière à l'Épaule flows through the lake from north to south, and a dam was constructed at the outlet of the lake some decades ago.

Access to the lake is available via the daily fishing access point (Accès Via Pêche Quotidienne), which serves as the primary launch point. A secondary road serves the western portion of the lake for forestry and recreational tourism purposes, and Route 175 — linking Quebec City and Saguenay — passes approximately 0.25 kilometres to the east. The lake is roughly 50 minutes from Quebec City by road.

Paddlers should be aware of submerged rocks near the western shoreline, where stones are frequently found at or just below the water surface. The northern end of the lake transitions into a marsh area that is notably shallow. A handful of SEPAQ (Société des établissements de plein air du Québec) chalets are present on the lake. Amenities at the access point include a boat ramp, campsites, picnic shelter, and picnic tables.

The lake is generally calm, though it is capable of producing strong waves and challenging currents, suggesting conditions can vary and may be more suitable for paddlers with some experience. The northern marsh area offers a distinct contrast to the open water of the main lake body and warrants careful navigation due to shallow depths. Given its location within a national park, paddlers should anticipate that park regulations and potentially permit requirements may apply.