Diana Cook and Dorothy Kirk confirm that Turner looked northwards from Colley Cliff on the Calstock to Gunnislake road, recording the Tamar at Weir Head (the limit of the tidal river) and the short, straight canal by-passing it, with Gunnislake on the slopes beyond; the view is now largely obstructed by trees, but they reproduce a photograph of about 1900, when the scene remained recognisable.1 Roughly the same view is shown in the slighter sketch on folio 139 recto (D09652).
There is a similar view from near the church at Calstock, further south, in the contemporary Devonshire Rivers, No. 3, and Wharfedale sketchbook (Tate D09835; Turner Bequest CXXXIV 40).
For other views along the Tamar Valley, see under folio 114 verso (D09606).
Cook and Kirk 2001, p.41, with a further photograph from about 1900 and a modern one by Kirk reproduced p.42; Cook and Kirk 2009, p.40.