Why did the Victorian government decide to offer a reward for the discovery of gold within 200 miles of Melbourne?

Payable gold had already been discovered in New South Wales. Victoria had pushed for self-government and separation from NSW, and now the government was keen to establish its own source of wealth. It was believed that, if gold was discovered within 200 miles of Melbourne, people would flock to the new colony, and Victoria would become a wealthy colony in its own right.

To this end, Governor La Trobe assembled a Gold Discovery Committee on 9 June 1851, and offered a £200 reward to anyone who found payable amounts of gold.