The rainforest at Robertson is known as the Yarrawa Brush. “Yarrawa” is Aboriginal for “a violent storm” and “brush” is an early word for rainforest. While an accurate figure may never be known, using currently available satellite-map technology to select the regions containing existing patches and the surrounding areas with suitable soils and sufficient precipitation, it is conservatively estimated that the central rainforest and the outlying areas at Knights Hill, Avoca, Wildes Meadow, and Macquarie Hill originally covered several thousand hectares.

The account of R. L. Campbell, who surveyed for selections in the brush during the 1860s, is also pertinent. Because of its dense tangle of trees, shrubs and vines, this rainforest was avoided by settlers long after other parts of the Southern Highlands were settled. In 1830 the surveyor, Robert Hoddle, with convict labour, had a bridle track cut through the forest to the coast. These were the first known Europeans to traverse what bushmen described as “the thickest jungle in the colony.” The track was soon overgrown and was unused until 1859. After John Robertson (the parliamentarian after whom the village was later named) had his NSW Land Act passed in 1861, selectors began the difficult task of felling the rainforest, most of which had been removed by 1900.

Some patches, however, remain in more or less original condition, especially on steep or stony sites unsuitable for farming or where forest was deliberately conserved by landowners.

The Robertson Nature Reserve, located within the village, is an example of such far-sighted preservation and other examples occur on private land. Elsewhere there has been considerable regrowth, resulting in a highly picturesque landscape of verdant pastures and fields, interspersed with lush forest patches.