He worked as a geologist in the United Kingdom and Canada, before moving to Newfoundland in 1864 to become the first director of the Geological Survey of Newfoundland. His first major task was to produce a reliable topographical map of the interior of the island. Murray did detailed work in the area between Hall"s Bay and Saint George"s Bay, as well as the area surrounding Conception, Placentia and Saint Mary"s bays.
He also mapped parts of the Great Northern Peninsula and central Newfoundland.
Murray produced the first geological map of Newfoundland and his reports of rich resources in the island"s interior were an important factor in the decision to build the transport-island railway in 1881. Poor health caused him to return to Scotland in 1883.