** Great Divide Mining GDM.AX jumps as much as 11.9% to A$0.47; marks biggest intraday pct gain since February 4
** Stock hits highest since April 23
** Diversified miner to begin operations at Challenger Mine Site in New South Wales this month; had taken over mine's ops in March
** Says gold produced from Challenger will be the mine's first contribution to GDM's revenue stream
** Stock has more than doubled YTD
(Reporting by Sneha Kumar in Bengaluru)
((Sneha.kumar@thomsonreuters.com;))