Complex sentence: The various roads classified as State Highway 19, were then named as the Monaro Highway in 1958; in contrast with the Snowy Mountains Highway, the entire length of that highway is within the Monaro region.
Split into simpler sentences: The various roads classified as State Highway 19, were then named as the Monaro Highway in 1958. In contrast with the Snowy Mountains Highway, the entire length of that highway is within the Monaro region.