The Southern Inland (SI) area of NSW covers a region that surrounds the ACT and includes the Snowy Monaro to the south, local government areas in the Canberra-Sydney corridor, farming regions to the north west of the ACT, communities west of the Brindabellas and the nearby communities of Queanbeyan, Palerang and Yass.
RDA ACT work closely with the RDA Southern Inland across the border in NSW, whose area encompasses the greater capital region. To that effect, the RDAs of the ACT and Southern Inland signed a Memorandum of Understanding in late 2010 noting the need for high level cooperation and coordination between the two organisations.
More information about RDA Southern Inland can be found on their website, as can their contact details.
A comprehensive overview of the region can be found in a background paper to their Strategic Plan, which can be found here.