The Pyrenees Highway was declared a State Highway in August 1938, cobbled together from roads between the Calder Highway at Castlemaine, via  Maryborough and Avoca to Ararat (for a total of 92.5 miles); before this declaration, these roads were referred to as Castlemaine-Maryborough Road, Maryborough-Avoca Road and Avoca-Ararat Road.
In August 1938, the Pyrenees Highway was officially recognized as a state road, connecting the Calder Highway at Castlemaine with Maryborough and Avoca before reaching Ararat (a total of 92.5 miles). Before this designation, these roads were known by different names: Castlemaine-Maryborough Road, Maryborough-Avoca Road, and Avoca-Ararat Road.