The canal was opened on 20 November 1829. Some time after 1834 and before 1839, Earl Morley's tramway was extended up the valley to Cann Quarry. Near the quarry, it was built on the canal bank, but lower down it was built further to the west. Once it was opened, the canal ceased to be used as a navigation and served as a mill leat for the corn mill at Marsh Mills. A branch of the tramway, which was built to the unusual gauge of , was constructed from Plym Bridge to the quarries at Lee Moor, and the whole railway became known as the Lee Moor Tramway. The South Devon and Tavistock Railway built a branch up the Plym Valley, which was completed in 1854. For most of its route between Marsh Mills and the quarry, it was built between Earl Morley's tramway and the canal. The new railway cut across the quarry, which closed the following year. Marsh Mills corn mill continued to operate until 1927, when the owners became bankrupt.