James Nash discovered gold in Gympie in Nash’s Gully in 1867. After which, it started a wild rush to the Gympie goldfields. The goldfields eventually yielded over £14 million worth. Gympie became known as the “town that saved Queensland”.

James Nash wrote his letter to claim of a viable goldfield to Maryborough dated 16 October 1867:

Maryborough
16 October 1867

Sir,

I do myself the honour to inform you that I have found a gold field in the Wide Bay District. It is situated between Carry? & Traviston about 50 miles from Maryborough. I have proven several gullys and feel sure there is profitable employment for a large number of miners and I hereby claim the reward offered for the discovery of gold fields by the government.

I have the honor to be your obedient servant.

James Nash

This item is held at Queensland State Archives:
https://www.archivessearch.qld.gov.au/items/ITM1137542

https://qalbum.archives.qld.gov.au/qsa/james-nashs-announcement-gold-gympie-1867

It was not always easy being the man who discovered a viable gold field as per this unfortunate event:

On 27 April 1868, Nash wrote to the Commissioner for Public Lands regarding his original letter and to the claiming of the reward offered by the Government for the discovery of new gold fields:

For the full article: http://nla.gov.au/nla.news-article188171830