The river rises between the peaks of Stony Cove Pike and Thornthwaite Crag in the High Street range, at a height of about 1,970 feet (600 m).

Several tributaries flowing from the crags to the west of the High Street Roman road combine to form the young Trout Beck.

At a height of about 650 feet (200 m) the Woundale Beck, draining the eastern flanks of Broad End and Pike How, is subsumed.

The engorged Trout Beck then skirts Hird Wood on its eastern side before subsuming Hagg Gill at the 460 feet (140 m) contour.

Continuing through a narrow area of mixed woodland the river eventually reaches the A591 road at Troutbeck Bridge near the town of Windermere.