A stiff 45m walk up the firetrail, watching out for mountain bikers, brings you to the base of the mountain, about 300m above the start point. From here there are two ways up. A clearly marked track starting at 673563 leads to an easy scramble through a break in the cliffs at 671563 that has you on the top in another 15m.
From here there are great views over Kangaroo Valley.
There is another way up that has a much wilder feel and offers great views into the National Park. Continuing along the firetrail you cross two deep gulleys. Immediately after the second, at around 673570, turn off into the wet forest and find a steep ridge running due west on the north side of the gully. It is steep, but the forest is open and easy going. The ridge leads to an effortless ascent through the cliffs at 671569. From here there are spectacular views along the north side of the mountain.
Also great views back to Fitzroy Falls.
Walking along northern cliffs, with wonderful views all the way, brings you to a second line of small cliffs. The northern end of these are little more than a rocky slope and from the top a faint track with occassional cairns leads to the Corrialoo trig point about 1.5km away at 687m - 427m above the start point. The landscape along this walk varies a great deal. It starts out as dry scrub with rock platforms.
There is even a rock overhang that would serve as a camping cave at 664565. There are interesting rock formations, like 'the nipple,'
and 'the picnic table'.
This is followed by a swampy saddle in the middle of the mountain with dense saplings and small pools of standing water, although that is not be relied upon. Finally the track ascends to flat, dry heathland, where the track becomes very clear, presumably because the vegetation does not regenerate easily, and arrives at the Trig point.
The track continues, presumably to a western descent point and the ridge to Mt Moollattoo, but we did not have time for this and returned via the northerly ascent point,
the steep ridge running east-west,
and the firetrail.
The ideal way to do Mt Corrialoo would be to ascend by the wilder, northerly route, explore the top of the mountain, and then come down by the fast, southerly route. That would take about six hours, allowing for lunch, photostops, etc, and make a more or less perfect day-walk.