As I drove there, I saw a Bassian Thrush beside the road. just past the Kangaroo River crossing (the main bridge) on the Carrington Falls road. It was between the Bridge and the turn in to the main parking area leading down to the main lookouts. This is across the River, not the popular swimming hole used by the locals, which is accessed by veering right, before the River crossing.
The Bassian Thrush is a fairly secretive bird, a little smaller than a female Bowerbird (which looks somewhat similar). Bowerbirds hop with both legs simultaneously (they "bounce") whereas the thrush runs low to the ground and moves quickly, once it decides to go. When I flies it has a faint light stripe along the wing. It has a mottled chest, and a dark olive/brown back. It has a large dark eye, with a pale ring of feathers around the eye.
Formerly known as "Ground Thrush"
However, I have more frequently seen them in wet sclerophyll forests around the bottom of Fountaindale Road (which is taller forest than at Carrington Falls, but not far away, "as the Thrush flies". I have also heard them and occasionally seen them beside the road to Belmore Falls, in what I refer to as sandstone scrub below Eucalypt forest, with many Banksias present in the vegetation mix. I know it is a very imprecise description, but it does not fit the classic definition of "wet sclerophyll forest" (as described by NSW Office of Environment - well certainly not the "grassy sub-formation") This is typical wet forest on sandstone around the southern Nepean River catchment and the northern end of the Shoalhaven River.
I drove on to Jim's place, where there has been a lot of clearing, and saw another Bassian Thrush beside the road beside a stand of remnant (maybe regrowth) forest on black soil, over shallow sandstone.
Then as I drove back several hours later, I saw another Bassian Thrush, not far past the entrance to the Carrington Falls picnic area. Possibly the same bird as previously sighted.
From notes i have been receiving from the Canberra Ornithologists group, it seems Bassian thrushes are starting to breed in and around Canberra, so this seasonal factor might explain their apparent more obvious feeding beside roadways around the local sandstone forests.