McMillan completed several expeditions, and while he was not necessarily the first to visit many locations, his explorations were the most important in terms of European settlement of Gippsland proper. On his final expedition he located a suitable port for the region, at present day Port Albert. The route established then by McMillan remains essentially the same major north-south route through Gippsland to this day. This route follows the Great Alpine Road south through the Tambo Valley to Bruthen, then west to Bairnsdale and Sale along the Princes Highway, then south from Sale to Port Albert.