Thanks Spoonie, I was thinking of perhaps going down the coast until Nowra then starting to come inland crossing near Ettrema Gorge (as I'd like to see that) ...
Elbo, I wonder if you have seen my trip report on 'crazyguy' about Galloping Jim's Route, that crosses Turpentine Road (the Nerriga-Nowra road)? ...
http://www.crazyguyonabike.com/doc/?o=1r4vFZo&doc_id=7644&v=BD
To see Ettrema, is no small feat. You would need to dump the bike in the bush at some stage and hoof it out to the cliff line. The top of Ettrema and Jones Creek can just be made out from the Turpentine Road. I've been down into Ettrema a few times. If you want to have a chat about a walking route, with the entrance and exit/s to the canyon or where to hide the bike, you are welcome to give me a call 02 62540295.
and either go down the Eastern side of ACT, then onto Cooma, Jindabyne and Kozi, or go into Victoria and then head North West over the mountains through Benambra or Omeo then Falls Creek. Otherwise I would try and get as much dirt in as possible before Jindabyne and then ride the road from Thredbo to Khancoban and then along the Murray River to Lake Hume and Albury.
Fat Guts advice through Snowball is good country. Through Snowball there are heaps of Travelling Stock Reserves to freely camp in. In the Cooma Region there are 104 TSRs that are free camping for touring cyclists.
The Benambra-Omeo route from Thredbo if you were thinking of heading on the dirt from Tom Groggin? A bloke from Canada, Graeme Challis, took on a small section of the Victorian High Country and crossed from Tom Groggin to Benanbra. He left the BNT near Mount Pinnabar, a most impressive effort in the heat ... his photos describe the trail and summer conditions well from Boggy Swamp at Tom Groggan, climbing to near Mount Pinnabar. "The World's longest shortcut" he called it ...
http://www.crazyguyonabike.com/doc/page/?o=1r4vFZo&page_id=179347&v=Gx
There is no way of going through the southern ACT to avoid some hills. A less steep option is through the Naas Valley and at Calloola Farm take the Gudgenby River Fire Trail to Brandy Flat (that route avoids the notoriously steep Fitzs Hill). Brandy Flat it isn't far to the Boboyan Road. Link to the Old Boboyan Road turnoff (below Yankee Hat). Follow the old road to Grassy Creek and join the Border Track to the BNT. This will take you down to Paycotle (at the saddle of the Yaouk Bill Range). Then its 13 ks down hill to Yaouk. To follow the Naas River Fire Trail (from Caloola Farm heading N to S) to the ACT/NSW border is slow-going hauling a touring weight. Going S to N, downhill in the Naas, is one of the best rides in the district for a tourer.
From the Grassy Creek/Border Track the trail down to Paycotle, is shown on maps as the track from the ACT Border to the property called Fairy Glen. If you take this track the Rangers at Namadgi will give you the combination to the gate ... or at the worst scenario you can ring me. I know the combinations for those on the BNT.
If you head to Adaminaby through Yaouk you take on Little Bear and Big Bear Mountains (wonderful riding though). The other option is to go over Lone Pine Fire Trail (from Yaouk) that will give you a few hours of hiking the bike before you head across to Oldfields Hut and onto Pocket Saddle Road. Going over Lone Pine and Pockets Saddle Road the resupply is limited at Providence. Over Big Bear, there is an excellent resupply in Adaminaby. at the Spar Supermarket. At Spar the excellent camping store is in the rear of the shop. Spar has Iso Butane and High Performance Isobutane, if you have a Kovea style cooker. Little Bear has one nasty section of 500m that not even Andy Shreck or Bertie Contradoper could ride. Just a steep half-an-hour hike-a-bike. The views are extraordinary looking down on the 'bidgee from Little Bear and Big Bear. The hike-a-bike to top Lone Pine takes about 2/2 1/2 hours.
On Kennedy's Road heading to Lone Pine Fire Trail. It is an awesome saddle to cross.
Once you summit Lone Pine the tracks above Tantangra Dam are as good is it gets. This is an old shot North of Tantangra Dam on the Blue waterholes Track, heading to Pocket's Hut.
Yaouk Road near Yaouk.
Almost at the bottom of Big Bear Mountain.
Through Providence, you can take the highway to Khancoban or go over the lake. There is a low water track and a high water track to cross the lake to the Tolbar Trail. From Tolbar you can turn off at Grey Mare FT and then head onto Jagungal. At Jagungal continue past Derschkos Hut to Wheelers Hut in the Dargals, then steeply down hill to the highway. Or keep following the BNT from Tolbar to Happy Jacks Road to Fifteen Mile Ridge, then join the highway down hill to Khancoban. Here you have an option of a side trip to resupply at Cabrumurra. Although Cabrumurra has only basic supplies. From Khacoben it is 30klicks to Corryong. At Corryong the camping store is in the back of the supermarket.
Overlooking the Farm Ridge Track to Jagungal from Round Mountain.
Camped below Jagungal. From Jagungal taking Schlink Pass will go downhill to Island Bend then the tarmac can be ridden around to Thredbo
Have you seen Micheal Rogers BNT track report? Michael traveled North from Healesville on the BNT to the ACT just recently. You could back track Michael's route from Yaouk and mix and match the tracks and back roads, that suit your time ...
http://www.crazyguyonabike.com/doc/?doc_id=8146
This image sums up the dirt roads across the mountains ... until you reach the snow grass country.
Your idea of traveling into the Blue Mountains (supported by Spoonie), is a good one. You can join the BNT at Rydell Railway Station. The BNT goes right past the station or just follow the quiet country roads through places like Mount Rae and Rosalind through to beautiful Lerida and across the top of the Lake George Escarpment (Marked Tree Road) to Gundaroo and then cross Canberra from Mulligan's Flat on the cycle paths. Have a look at Mulligans Flat wildlife enclosure if you haven't seen it, I fully recommend this side trip.
View from Marked Tree Road.
The Trunk Road at Mulligan's Flat is like billiard table surface and the Old Coach Road to return on, is just as good ... but more rustic looking.
A sign to the Charny Shops is a cycle path sign to nowhere. I don't know if you have ridden Canberra's cycle paths or on the on-road cycle lanes, they are a gift despite the signage.
These are just a few options for crossing the Northern Alps, if coming through Canberra becomes an option. I know the tarmac roads and the dirt tracks and fire trails in my district ... the dirt is very classy. Sorry I don't have web maps the SE, it is in my head. High quality well maintained fire trails and back country roads here are all little visited by touring cyclists. On the dirt there are very few vehicles to contend with, if any at all ... unlike the few tarmac roads which channel heavy traffic. There are so many options on the dirt, and not many on the tarmac.
I hope this helps. Good luck and have a good adventure.
Warren.