The Misty Valley Branch Line goes from the Peel Godred Branch Line, south of Peel Godred to Lord Callan's Castle. Callan, Black Loch and Lord Callan's Castle are located here. Cyril the Fogman also lives close to this line in his cottage.
The branch line was introduced in the fourth season and appeared up until the eleventh season. The branch line and Callan Castle were reintroduced in full CGI in the fifteenth season.
The line begins just south Peel Godred and travels up to Callan, then through Misty Valley and the line ends and loops around at Lord Callan's Castle.
No engines have worked on this line, however during the fourth season Duck, Oliver, Donald and Douglas were often seen working at Callan. Thomas, Edward, Henry, James and Percy have also been working on line. Emily worked the line for a while. This started in Emily's New Route, when she first saw Black Loch.