The Mary Valley railway line was a branch line of the North Coast railway line, which branched west at Monkland (just south of Gympie) and continued to Brooloo in the upper Mary Valley. It was constructed between 1911 and April 1915 to facilitate closer settlement of the Mary River valley. The line reached Kandanga railway station in February 1914 and the terminus of Brooloo in April 1915. In March 1920 an extension of to Kenilworth was approved at an estimated cost of £175,000. However, the extension was never constructed.