The line begins several miles north of Hawin Lake, near Whiff's Waste Dump and travels northeast up to the Sodor Slate Quarry and connects up with the Skarloey Railway at the Blue Mountain Quarry. Mavis sometimes works on the line at Sodor Slate Quarry. Several engines including, Thomas, Henry, Gordon, Toby, Stephen, Gator and Samson have been seen at the Blue Mountain Quarry. Paxton also uses the line to bring stone from the Blue Mountain Quarry.