• Distance 32km
  • Altitude max 1353m
  • Altitude min 923m
  • Trail type Return
Three Stars

Three Stars

Worth Doing

The Australian Hiker Experience Rating is a measure of the overall quality of a walk. It is intended to help you decide whether to walk a trail, not to measure anything objective. Consider this our personal take on the walk.

Grade Four

Grade Four

Bushwalking experience recommended. Tracks may be long, rough and very steep. Directional signage may be limited.

The Australian Grading system is based on the australian standard for measuring trail hikes.

Rubbish Bins
Camping Grounds

Cotter Flat ACT (32 km)

Bimberi Wilderness

Starting Location

Orroral Valley Tracking Station (former) carpark

Carpark at Orroral Tracking Station

Finish Location

Orroral Valley Tracking Station (former) carpark

Best Time to Travel

October and March

This trail is walkable year round it can however be prone to snow from between April and September at higher elevations so come prepared. The heat can be oppressive between November and February so if you are walking during the summer months it is best to start early and take breaks during the middle of the day to avoid the heat

Cotter Flat Trail Summary

The walk to Cotter Flat in the Australian Capital Territory (ACT) is part of the Australian Alps Walking Trail (AAWT). I do this trip at least three times a year as a day walk if I’m feeling energetic, or as an overnight walk if not. I also use this walk as my shakedown hike when I am changing gear. This walk starts at the site of the decommissioned Orroral Valley Space Tracking Station. The facilities provide a great day picnic or overnight camp in its own right with a decent toilet block, picnic tables and gas barbecues. Please note there are no facilities at Cotter Flat.

The walk to Cotter Flat is approximately a 5-6 hour walk depending on you fitness level and pack weight. The trail starts off with a 5.8 km walk along one of the fire trails before turning off the road onto the AAWT proper. The turnoff point is easy to miss so start paying attention at about the 5 km mark and look to the left side of the road (there is a photo of the turnoff point below).  Once you turn onto the side trail, the track is undulating for about 1 km before a steep incline towards the top of the hill at Cotter Gap. Camping is possible in this area although not recommended.

From Cotter Gap the trail undulates but is mainly downward and in relatively good condition although tree falls on this trail are common so you will usually have to climb over/under or around logs of various sizes. The trail continues downwards to Cotter Flat at approximately the 15-16 km mark. Cotter Flat is one of the best camping areas in the area with flat grassy ground kept short by the large local Kangaroo population, good access to water and good wind protection. Camp well away from any large Eucalyptus trees as it is not unusual to hear large trees falling in the middle of the night particularly during periods of high winds and heavy rains. In addition, you are required to camp more than 500 metres away from the rangers hut on the opposite side of the river.

I highly recommend Cotter Flat as the place to pitch your tent. If you are progressing on to the summit of Mount Bimberi, use this area as your base camp. There is something about this hike that I never of.

The return trip to Orroral Valley is approximately 5-6 hours for walkers with good fitness. The hill leading up the Cotter Gap is the only serious one of the return trip and is much easier than the trip out. The last 5.8 km walk along the fire trail back to the tracking station can be a bit monotonous but the road surface is always in good condition.

Carpark at Orroral Valley Tracking Station

Toilet block. Note the space age design that references the Tracking Station

Bushwalking register: remember to sign in and out

Picnic and barbecue facilities at the carpark

Example of a typical section of trail

Camping amongst the small wattle trees on Cotter Flat

Fringe flower; just one of the wildflower examples present on the track throughout the year

The Cotter River. This is where you cross the river if decide to walk to Mt Bimberi

Getting there

The former Orroral Valley Tracking Station complex provides an excellent carpark from which to base a number of walks in this region. To get to the tracking station drive from Tharwa approximately 30 km from the Tharwa Bridge along the Naas Road to the former Orroral Valley Tracking Station.

Travel along Naas Road (this road changes to Boboyan Road) past Apollo Road and turn off onto Orroral Road which is approximately 18 km from Tharwa on the right. Continue on Orroral Road past the campground and the road will finish in the tracking station carpark approximately 10 km from the turnoff. If travelling in the summer arrive early in the morning to get one of the shaded carparks that will keep your car cool for the day.

Starting point for this hike is the old Ororral Valley Tracking Station

Things to know

    • Phone: There is almost no phone signal on this trail (Telstra).
    • Water: You can top up your water along the way but bring a filter. The destination point of this walk at Cotter Flat has a river
    • Toilets: There are only toilets at the trail head
    • Trail: This walk is on formed trail and management road
    • Dogs: Dogs not allowed
    • Camping: Camping allowed but you need a permit in the Bimberi Wilderness that can be obtained by contacting the Namadgi Park Visitor Centre
      • If you are camping check your campsite prior to pitching your shelter and before putting on footwear as there are species of Funnel Web spiders in this region
    • Other: 
      •  Brown snakes are  common in the drier parts of the trail during the warmer months so use tracking poles in areas of long grass
      • Camping is limited in the Bimberi Wilderness and you will need a permit that can be obtained by contacting the Namadgi National Park Visitor Centre. During periods of drought there are at least four dependable water sources from the various creeks and rivers on the trail
      • No fires are allowed in the Bimberi Wilderness
      • The Horse flies in this area have a really good work ethic. They usually start halfway up the hill to Cotter Gap and will try to bite you through your leather boots, are capable of biting through a merino top, and don’t care one little bit about 80% DEET.  Shorts and short sleeve tops are best avoided unless you want to spend much of the trip battling these flies. They are bigger and nastier during periods of drought
      • The Kangaroos at Cotter Flat are thieves. If you leave food out at night they will take it. Every time I have camped here they have come and investigated the cooking area once we have gone to bed for the night
      • Avoid camping under large trees particularly during rainy and windy nights as it is very common to hear several very large trees go over at night time and this is evident on the trail itself


This walk was open by the team from Australian Hiker

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