At that time the quarry was operated by Lanark County Council and named Cairngryffe after the hill which formed the deposit. In 1935 the council closed down other smaller quarries nearby and installed what was then a state of the art crushing, screening and asphalt coating plant at Cairngryffe. This meant that all the roads in Lanarkshire were bright red in colour.
Cairngryffe operated as a local authority quarry until 1986 when it was taken over by the current operating company who replaced Tilcon at Cloburn quarry, which was located on the other side of Cairngryffe hill, in 1982. Today the two quarries have been joined to become one of the UK's largest mainland quarries supplying high quality granite aggregates to a wide range of customers throughout the UK, Europe and the Far East. A recent planning grant has secured its future well into the 21st Century.