Here's an interesting alternative ending....
After crossing the railway, drop down to the river bank immediately and you'll see what remains of bridge footings which provide great viewpoint up and down a narrow, steep sided channel.

Turn right and follow the small path alongside the river downstream - twisty, narrow and muddy/sun-dappled depending on your luck with lots of places to scramble down to the riverside - and eventually you glimpse the ruins of Bunroy Corn Mill 20m back from the riverbank and worth a quick look-see for the amazingly thin millstone propped up inside one corner.

Carry on downstream along the Spean riverbank path until you pop out into the lower campsite field. Stick to the edge of the field and drop back into the woodland again. Not much further on you'll see the river broaden out where it meets the River Roy and forms a wide, deep pool so perfect for swimming that they used to hold competitions there.

Swing round to the right and follow the path upstream along the River Roy. It climbs up at the end to a stile by the road leading back into Roybridge under the railway.