Sentry Box Mountain
Namadgi National Park
Australian Capital Territory and NSW.
In the far south of the Australian Capital Territory, straddling the border with New South Wales, lies Sentry Box Mountain, (1727 m). It is a huge block of a free-standing mountain, with a long, slightly curving summit ridge of granite slabs and tors and some scrub. The highest point is at the south-eastern end, while Sentry Box Rock (1673 m) is at the northern end. Many people ascend more or less directly to the summit from Sam’s Creek Fire Trail to the east. I have preferred to go up from the west and to go to Sentry Box Rock. This involves a climb of about 570 m. Sentry Box Rock stands right on the northern edge of the mountain and stands out from many directions, even though it is not very tall. Both routes are off-track.
I commence climbing from about GR 702, 337 climbing diagonally up the southern side of the valley through attractive, open forest of tall eucalypts and huge granite boulders, to come out on a very shallow saddle at GR 714, 343. Here one is right on the tree-line in snow gums and grasses. One now walks more or less straight for Sentry Box Rock, soon breaking out of the trees and wending a way through large boulders until the final summit ridge granite slabs are reached.
Sentry Box Rock is a good spot for lunch with extensive views over wild, rugged mountains in Namadgi National Park. About 5 km to the north north east Mt Gudgenby stands proud, while to the north west is the Scabby Range, the source of the Cotter River.
To the immediate west are the grasslands of Bradley’s Creek, while to the south west is the massive Yaouk Peak, of which I have already written. Far away on the horizon to the south west is the faint blue bulk of Jagungal Peak in the Snowy Mountains. A way off to the south east is the Clear Range in the A.C.T.
From Sentry Box Rock my route is now south along the mainly rocky and slabby summit ridge to a saddle just past a rocky and scrubby knoll at about GR 715 337. It is usually too far on a day hike to go on to the actual summit. I descend from this saddle, staying on the northern side of the creek. Great care is needed down here as this gully is very steep and often loose, covered in vegetation with plenty of rocks, fallen timber and bark on the ground and also unseen holes.
As one descends one becomes conscious of the very craggy ridge following one down on the right. Eventually this craggy gully side eases back, one realises that the contours are easing back and one is suddenly in beautiful tall, fairly open forest. This is an indication of a needed change in direction. From about GR 705, 328 I start to head north west, more or less following the contours. This is delightful, easy walking.. I go over the saddle at GR 698, 335, and follow the slope down until I join my outward track and so back to the car (s).
Go at the right time of the year and you will see many wildflowers, including orchids.
I have been up there in all weathers, but one particular walk stands out. It was August and there had just been a dump of snow. It was a sombre, grey day. A gale was blowing, and fine snow was being blown by the wind. None of this was known in Canberra where the weather was much milder and pleasant, even though relatively close. On Sentry Box Mountain, however, it was very cold and the cold increased as we gained height, as did the wind. Off-setting the general greyness and the darkness of the trees and rocks was the incredible clear yellow of the wattles in flower.
The leader had accepted a person on this club hike who is very slow. She needed to stop frequently to catch her breath and this meant the rest of us could not walk quickly enough to keep warm. In reality, she was a danger to the party and should not have been there. We finally stopped just short of the summit slabs, in the trees, to get some shelter. I remember that lunch stop well. The gale was still blowing hard and still whipping up the snow. We put on all our extra clothing and yet were still cold. 6 of us stood with our backs to the wind eating our lunch, feeling very cold and just wanting to get going again. Once we had eaten, the leader thought we should go to Sentry Box Rock despite our protests. Undaunted he set off onto the slabs only to go base over apex. The summit rocks were coated in ice. He beat a hasty retreat. We now realised that it was too dangerous to continue either to Sentry Box or to return along the route I have just described. We turned around and went down the same way. However, this was to have repercussions which , with distance, provide some humour.
Early on in the walk one of our number decided to return to the 2 cars and was given the keys to one of them. In order to save us some time at the end of the day, the leader suggested that if, later in the day, she wanted to, she could take the car and position it 3 km down the road. Now however, we were returning by the same route in, and when we arrived back at the road she was gone and we had only one car. We were all wet, cold and tired. We somehow squashed into the one 5 seater car and went down to find the other car. We drove for 5 km but she was not there. So we now retraced our steps and then drove 8 km the other way. We then tried another side road to no avail. We turned around and as we got back to our morning’s departure point she came driving up. She had positioned herself not 3 km down the road, but about 8 km. We were most relieved to find her as it was now getting dark.
Sentry Box is a lovely walk, giving a great mountain day, a great deal of variety, with almost no bush-bashing. It is in real wilderness, remote, and in wild and rugged country. To be on the summit ridge on a lovely day is magical, a time for dreaming. The route I have described is about 12-13 km.