This walk was organised and led by me as an irregular CBC Tuesday walk:

Tuesday 4 August - Gigerline Nature Reserve and Gorge to Mt Rob Roy - L/M-R,X. From Tharwa, up the Murrumbidgee past the De Sallis cemetery in the Gigerline Nature Reserve. Cross the river to Gigerline Hill. Back through the Murrumbidgee gorge then up Guises Creek into the Rob Roy Nature Reserve. Rose trig, Mt Rob Roy, Big Monks and down to a second car in the SE corner of Banks. Around 23km and 750m climb. Route not fully known to leader. Maps: Williamsdale and Tuggeranong. Limit of 8. Leader: John Evans – jevans@pcug.org.au, (h) 6288 7235. Transport: ~$5. Further details at http://jevans.pcug.org.au.

9 of us drove in 2 cars to park on the Canberra side of the Tharwa bridge. We left a third car up in Bellchambers Cres Banks.

Walk

Thanks to advice from Rob H, the planned route was changed to avoid blackberries along the Murrumbidgee River in the W flowing section S of Gigerline Hill. Val J at the Tharwa Store kindly passed on the contact details for the lessee of the land on the E side of the river S of Tharwa bridge and the property owner gladly gave permission for us to walk that side of the river to the start of the Gigerline Nature Reserve. So wet legs were avoided on a winter's day.

We started through wombat territory, some of the holes quite large in the easily dug river banks. No wonder the farmer had erected a fence parallel to the river - it keeps his cattle away from the holes and the river (it does not define any sort of public access river corridor). Opposite the De Salis cemetery and the spot where the Gudgenby River joins the Murrumbidgee, I took a snap. This area is Site of Significance in the ACT T37 Gudgenby Confluence (see pic 1).

From here we wandered S and SE along the quietly meandering Murrumbidgee, through the Tharwa Sandwash area until a convenient spot presented itself for us to climb away from the river towards Gigerline Hill. Puffing up the slope we could see the next Site of Significance in the ACT - RR5 Mt Gigerline Escarpment (see pic 2). Not being a geologist, the reference material describes sandstone outcrops which were visibly different and you could feel the soft sandstone.

The usual quadruped trig on Gigerline Hill, but a lovely view sweeping W through S to E over rolling open hills from the top. The Tinderrys were on the SE horizon, the Murrumbidgee River gorge beckoned us to the S and fog still covered Mt Tennent to the E. Some nice specimen trees about, including Kurrajongs and a starkly ring-backed eucalypt (see pic 3). There are scared trees in the area and an excellent 'canoe tree', but the locations are a carefully guarded secret not known to me. Near to the summit, Barrie pointed out a native hop bush (Dodonea angustissima, see here and here). Thanks for that info, Barrie.

The open knolls and saddles to the S of Gigerline Hill took us S then SE to the N (downstream) end of the Murrumbidgee River gorge. A line of hopeful depth marker poles marked the way down a drainage line to the river - many years since these have been wet. Plenty of different vegetation styles. Black Cypress Pine (Callitris endlicheri) is plentiful on the W bank and there were patches of Burgan (Kunzea cricoides) - so the doco says - to bob through as we followed the wombat trails. The area is Site of Significance in the ACT RR8 Guises Creek and Murrumbidgee River Gorges (see pic 4). Alternating sandy patches and dry rock hopping as we made our way along the gorge to morning tea.

We completed the 2.5km of the gorge and turned NE into Guises Creek gorge, the other part of SoS RR8 (see pic 5). 'The gorge of Guises Creek is cut into a coarse-grained rock with a granitic appearance initially termed the Tuggeranong Granite. It is now interpreted to be a volcanic member of the Colinton Volcanics and is designated as the Tuggeranong Tuff.' How about that - wonder what it is now, as the reference material is 30 years old. And I thought the Tuggeranong tuffs lived in parts of the Lanyon valley. An excellent little scramble up through here, but after about 700m we had to strike away up a minor drainage line more to the N.

At last out onto flatter, more open country and so to join a fire trail to enter the Rob Roy Nature Reserve. It took us up a typical dry and sad spur and with a mutiny brewing around noon we stopped on the high side of the trail for lunch. Views to the E over Royalla.

More fire trail took us N, until the greener adjoining slopes to the W (and conveniently on the heading for Rose Trig) beckoned us off the hard surface onto the softer ground. Sorry Brian, I now realise we were on your property again for a while. The day had cleared by now and Rose Trig provided sweeping views to the W, with Mt Tennent the central feature (see pic 6). To the N stretched the Canberra suburbs, with our destination of Big Monks closer at hand. It looked close and easy to reach over the rolling green hills, but our route lay 200m higher via the treed slopes of Mt Rob Roy. A corner concrete pad of the trig was inscribed 1973.

NE from here along softer fire trail, to the area at the top of Telephone Gully. Here Ken's local knowledge came in handy and we readily agreed to leave the fire trail and head directly to Mt Rob Roy. Open dry sclerophyll forest was our going as we climbed to the top.

The Rob Roy Range is Site of Significance in the ACT RR2. Not much of a view from its summit with the trees blocking any view, but a unique style of trig (see pic 7). Doesn't remind me of the Scottish Highlands.

And so NW along fire trail to Big Monks. The breeze was freshening and the clouds hiding the sun, so it was cool. Big Monks with its trig and tree and cleared surrounds is, to me, quite a cameo spot. Ken said that he'd seen hang-gliders launch from the saddle between it and the lone Kurrajong tree at 'Little Monks'. Time for a group photo, then the plunge down the side to Banks and the car.

Retrieved the other cars and that was it.

A walk with a little of everything in an interesting area. Great company from Cynthia B, Karen C, Eric G, Henry H, Barrie R, Chris R, Max S, Ken W.

Thanks also for your generous sponsorship for the Walk for Uganda!

Distance: 21.8km  Climb: 850m.  Time: 7.25am - 3.55pm (8hrs 30mins), with 50mins of stops.
Grading: L/M-R,X; H(13)

KMZ file for Google Earth/Maps: Gigerline Nature Reserve and Gorge to Mt Rob Roy