Rannoch - Ossian Loop 2
Route 2  Rannocch and Loch Ossian,  OS 50, OS 42, OS 41
Leave car at Tyndrum. Head N over Beinn Odhar to Auch (or follow West Highland way), From Auch up onto Beinn Dorain (rough) and along the Beinn Dothaidh, Beinn Achaladair ridge to Beinn a Chreachan. (alternatively follow WHW to Bridge of Orchy and take path onto Beinn Dothaidh). From Beinn a Chreagach drop down to railway line to pick up path through Rannoch forest leading  to Bridge of Gaur at W end of Loch Rannoch (not sure of the conditions of this section).  Then head west to pick up the path N up Allt Eigheach. Fork L over to Loch Ossian(or over tops) and down to Corrour station and train back to Tyndrum.
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Dave marsh on scottexservices.com