Murdo (1852-1929) was a son of John Mackenzie and Flora Macinnes, 4 Gravir.

In Lochs, in 1879 he married Mary Maclennan, 28 Gravir. Murdo and Mary settled at 28 Gravir and they had four children. After Mary's death in 1886 the family moved to 4 Gravir where Murdo built a house on his father's croft. 

In 1889 living at New Harbour, Wick he married Ann Kennedy, 2 Calbost in Pultenytown, Wick where presumably they were engaged in the herring fishing. Murdo and Ann settled at 4 Gravir and they had four children.

Murdo was an energetic community leader in his day, combining the roles of crofter, shoemaker and compulsory attendence officer ("whipper-in") in Gravir and Lemreway schools from 1916 with being an elder in the Church of Scotland from 1913.