Trail summary
Safety advice
Bushwalking experience is recommended, as tracks are long, rough, and steep, with limited directional signage. ​​
Hike overview
Mount King William I, located in the heart of Tasmania’s Franklin-Gordon Wild Rivers National Park, offers a rewarding but often overlooked adventure. This 11 km return hike is graded 4, which means it’s considered a challenging trek suitable for experienced walkers. On average, it takes about five hours to complete, with the summit rewarding you with sweeping views of the surrounding wilderness.
The mountain lies just south of the Lyell Highway, which connects Hobart to the west coast. Situated roughly 10 km west of Derwent Bridge, where you’ll find the turn-off to Lake St Clair, the mountain is visible from a small roadside rest area, making it easy to spot as you travel along this scenic route. It’s the northernmost peak in the King William Range, with Mounts King William II and III lying further to the south.
To begin the hike, turn onto Harbacks Rd, located about 1.5 km south of the Lyell Highway. The track follows the path of old, degraded roads as it heads southwest. After about 2 km, the incline starts to become noticeable. Initially, the climb is steady, but it soon becomes more challenging, with the track ascending more sharply as you approach the summit. After around 4 km, the track takes a steep turn to the west, and then heads south to reach the top of Mount King William I, just under 1 km from the old road.
Once at the summit, take time to pause and absorb the vastness around you. The peak is home to a helipad, three communication towers, a shed, and the remnants of an old concrete slab—evidence of the mountain's utilitarian past. Despite these man-made features, the natural beauty is unmistakable. The views to the east are stunning, with long ranges of forest-clad mountains stretching into the distance. To the north-east, the distinctive peaks of Cradle Mountain-Lake St Clair National Park come into view, providing a breathtaking backdrop.
This hike is not for the faint-hearted. The steep inclines can be demanding, and the exposed alpine conditions can become hazardous in poor weather. If you plan to tackle Mount King William I, be sure to come well-prepared, as conditions can change quickly in this rugged part of Tasmania. But for those who are ready for the challenge, the sense of accomplishment and the stunning scenery make the effort worthwhile.
Map and GPX file
Max elevation: 1295 m
Min elevation: 759 m
Total climbing: 543 m
Total descent: -543 m
Getting there
To reach the trailhead, head towards the Lyell Highway via the route that best suits your location, aiming for the Great Lake region. From there, travel through the town of Miena, and about 5 km past Miena, where the road starts to head north again, look for Marlborough Rd. (also known as Marlborough Hwy), with the Great Lake Hotel as a landmark. Turn left onto Marlborough Rd. and follow this gravel road for approximately 30 km, passing Bronte Park, until you reach the Lyell Highway.
Turn right onto the Lyell Hwy and continue west for another 30 km to Derwent Bridge. After passing through Derwent Bridge, continue for approximately 9 km. Cross the Little Navarre River, then the Navarre River, and about 150 metres past the Navarre River bridge, turn left onto Harbacks Rd. Follow Harbacks Rd. south to the junction of Mt King William I Track. There are small parking areas near the trailhead.
Track grade
Grade 4 (Hard) - Challenging Walks for Experienced Walkers: Grade 4 on the AWTGS signifies challenging walking tracks. Bushwalking experience is recommended for these tracks, which may be long, rough, and very steep. Directional signage may be limited, requiring a good sense of navigation. These walks are suited for experienced walkers who are comfortable with steeper inclines, rougher terrain, and potentially longer distances.
About the region
Franklin-Gordon Wild Rivers National Park, located in western Tasmania, offers a dramatic landscape of rugged mountains, deep gorges, and pristine rivers. The park, situated approximately an hour’s drive from Strahan, is part of the Tasmanian Wilderness World Heritage Area. The Lyell Highway provides convenient access to short walks with scenic views of the Franklin River, while cruises from Strahan explore the impressive Macquarie Harbour and Gordon River.
The park is historically significant for its role in the major conservation battle of the 1980s, which successfully protected the Franklin River from hydro-electric development. With more than 1900mm of annual rainfall, the park features lush vegetation, including wet temperate rainforest, buttongrass moorland, and eucalypt forest. This diverse environment supports a range of native wildlife, including the Tasmanian devil, spotted-tail quoll, and platypus.
The park also holds cultural importance with several Aboriginal sites, reflecting the southernmost extent of human occupation during the last ice age. The colonial history includes the grim penal settlement on Sarah Island and convict logging operations, which lasted over 150 years. The old Linda Track and the Lyell Highway were crucial for accessing the region’s resources.
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Gear to consider
What you carry in your pack depends on factors like weather, terrain, time of year, the type of adventure, and your personal preferences. Unsure what gear to bring? My free planning, food, and packing checklists offer a great starting point, covering essentials for day hikes, overnight trips, and multi-day adventures. Use them as a guide to customise your kit to suit your needs, always prioritising safety above all else.
Explore safe
Plan ahead and hike safely! Always carry enough water and pack clothing layers to adapt to changing conditions. Bring essential safety gear, including a torch, a Personal Locator Beacon (PLB), and a reliable communication device. Check official government sources for trail updates, temporary closures, and access requirements. Before heading out, review local weather and bushfire advice, including warnings and planned burns. Most importantly, let someone know your plans before you go. Being prepared ensures a safer and more enjoyable hike! Stay Safe, Explore More, and Always #ExploreSafe
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Acknowledgement of Country
Trail Hiking Australia acknowledges the Traditional Owners of the lands on which we hike and pay respects to their Elders, past and present, and we acknowledge the First Nations people of other communities who may be here today.