Tumbarumba is a town in New South Wales, Australia, about 480 kilometres southwest of the state capital, Sydney. Tumbarumba is loc…Tumbarumba is a town in New South Wales, Australia, about 480 kilometres southwest of the state capital, Sydney. Tumbarumba is located on the periphery of the Riverina and South West Slopes regions at the western edge of the Snowy Mountains. The 2016 census showed the population of the town and surrounding area to be 1,862 people. Locals refer to the town as 'Tumba'.