The Bonnar name has been well recognised in the construction industry since the company was founded in 1962. The company's main interests were in haulage and general construction with the key move into quarrying in 1972.

It was 1981 which brought about the biggest change, when after many successful years in business the company took a major step in expansion as a result of increased customer demands. Clachan Quarry a 25 hectare sight in Cairndow was chosen for its uniqueness.

Market forces dictate that the quarry supply the complete range of quarry products. The recently introduced Bagging Plant means that material can be marketed loose or in 25kg, 40kg or 1 tonne bags. Both the 25kg and 40 kg bags are designed for ease of handling and convenience. The bags are sealed preventing any spillage and waste. Other materials including red granite, windstone blue, chips and golden gravel are also supplied from stocks