The name "Markham" commemorates Sir Clements Markham, Secretary of the British Royal Geographical Society - Captain John Moresby of the Royal Navy named the Markham River after Sir Clements in the course of his voyage of exploration in HMS Basilisk in 1873.
The inhabitants of the valley are of Oceanic (Austronesian) descent and live in large villages under a chieftain political system.
According to one visitor, about once a year, the local Papua New Guineans burn the dry grass.
[citation needed] The Markham Valley runs from the port city of Lae up to the junction of the Highlands Highway and the road to Madang.
The dominant land use in the valley is as cattle pasture, with some sugar-cane production and chicken farming.