["< sod > the'''blue bird mountain quarry'''( officially first introduced in'' [ [ blue mountain mystery ] ]'' ) is a large slate quarry, located somewhere on another one of the narrow gauge lines of the skarloey railway. < eod > < 1 sod > formerly the'''blue mountain quarry'''( first introduced in'' [ [ blue bird mountain mystery ] ]'' ) is a large slate quarry, located on one of the narrow gauge lines of the skarloey light railway. it is also served by a standard double gauge branch line that crosses breaches of the peel godred line. < eod >"]