The Orchy rises in the Black Mount Forest where its waters within the Deer Forest include the Island Pool and the Elbow Pool. After a run of , in which it receives the waters of several large burns, it expands into Loch Tulla. Between Loch Tulla and Loch Awe, the river runs for . It passes through Glen Orchy in a narrow channel. At Dalmally Vale, the river spreads into wide shallows, accumulating on banks. At the point of a shingle island, the Orchy flows through a cultivated strath, about wide. The river merges with the waters of Loch Awe at Kilchurn Castle.