In 1870, Fraser emigrated to Western Australia to take up the position of that colony's Surveyor-General, which had become vacant on the retirement of John Septimus Roe.

As surveyor-general, Fraser immediately became a nominated member of Western Australia's Legislative and Executive Councils.

He remained surveyor-general until 5 January 1883, when he was appointed to succeed Edric Gifford as Colonial Secretary of Western Australia.

Under responsible government, the Executive Council was dissolved, and the office of Colonial Secretary became a ministerial portfolio.

Throughout his life Fraser had a reputation for his bad temper, being described as "a man whose intemperate habits had been town gossip for years".