By 1860 a track from Gladstone to Bowen included a section from Marlborough to St Lawrence, but it ran inland from St Lawrence and did not proceed along the coast to Sarina. A likely route for the section of track from St Lawrence to Nebo is attached. A few years later a track through low-lying swampy country was established from St Lawrence to Sarina and Mackay. By the late 1800s this track had become a widely used but difficult coach road. In the 1920s motorists began using this road. In 1940 the coast road was still in poor condition and it was decided to build a sealed inland road from Marlborough to the Sarina–Clermont Road (now the Oxford Downs–Sarina Road) near the location of
Wandoo pastoral station. Progress was slow, but by 1949 a track had been cleared and some bridges built. Bitumen sealing commenced in the early 1950s. Work continued until 1962, when the bitumen seal was completed, but much of it was only to a width of . This was the first sealed road from Marlborough to Sarina and became part of the
National Highway. Between 1962 and 1973 the widening of bitumen seal and narrow bridges was undertaken. == Major intersections ==