Lake Murchison is a hydroelectric reservoir in western Tasmania, created by the Murchison Dam — a concrete-faced rock-filled embankment dam completed in 1982 by the Hydro-Electric Commission. The reservoir impounds the Murchison River and is also fed by George Creek, the Anthony River, and discharge from the Tribute Power Station. It sits within the northern part of the West Coast Range, near the town of Tullah, and forms part of the broader Pieman Power Development system operated by Hydro Tasmania.

The lake is most commonly encountered as part of a multi-day packraft or canoe traverse, typically as the final major water section before reaching the access road at Tullah. Paddlers completing the Murchison River route from the central highlands — a trip that has been done in approximately five to five-and-a-half days from Cynthia Bay — arrive at the lake after descending the river through remote, easy-moving water before encountering the impoundment.

The crossing of Lake Murchison is widely regarded as the most demanding section of this route. The lake is prone to strong headwinds, and paddlers should be prepared for a sustained, physically taxing effort to reach the far end where the access road is located. There are very few opportunities to beach along the shoreline, as the lake margins are lined with submerged dead timber and snags that make landing difficult and pose a puncture risk for inflatable craft. Paddlers have reported being unable to find a suitable lunch stop and resorting to floating in the middle of the lake to eat. The combination of wind exposure, limited rest opportunities, and the sheer length of the crossing means tired arms and a late arrival are realistic outcomes.

The lake's character is shaped by its origins as a flooded valley — submerged trees and branches are present throughout, particularly along the edges, and these represent a genuine hazard for packrafts and other inflatables. Paddlers should plan to keep moving once on the water and not underestimate the time and energy required to complete the crossing. The access road at the far end of the lake near Tullah serves as the standard takeout point for this route.