Rock Dunder Loop

Dogs Leashed

Features Geological Significance · Hot Spring · Lake · River/Creek · Views

Rock Dunder is a treasure that lies within the UNESCO Thousand Islands Frontenac Arch Biosphere Reserve. Rising 275 feet above Morton Bay, Rock Dunder provides breathtaking views of the surrounding lakes and woodlands. Trails lead to one of the highest points of land in the area, and offer stunning vistas that are enjoyed seasonally by local residents and visitors to the area. For many, childhood memories of running trips to Rock Dunder remain fresh in their minds.

Day Passes: Purchase online here. Passes will also be sold at the Rock Dunder trailhead.

Day Pass per hiker: $5.00
Group Day Pass for 3-6 hikers: $15.00
Groups of more than 6 hikers: RWLT
Children under 6 years of age accompanied by an adult: no pass required

2021 Season passes can be purchased here for $60 each

RWLT does not control arrival and departure times of visitors. A supporter pass does not guarantee a parking place. When on-site parking at Rock Dunder is full, visitors should use off-site parking to the north. There are No Parking areas signed on the shoulder of Highway 15 near Stanley Lash Lane. Cars parked illegally may ticketed or towed: the OPP enforces the No Parking areas.

At the parking lot, take the left fork onto Summit Loop. Follow a gentle trail through alternating forest and exposed Canadian Shield for about 1.5km, then the terrain starts to get a little bit steeper. The Rock Dunder Summit is at about 2km along this trail, and is a large exposed rock with many outcroppings. Expect it to be reasonably busy here, but it's a great spot for pictures.

Continue along Morton Bay, and you run parallel to the water. You'll pass two different cabins that were previously used by Boy Scouts for camping in the area. There are a few rest stops and benches along the route. At about 3km, the Summit Loop ends and you'll encounter a fork. The right fork is Cabin Trail which is an easy way back to the parking lot.

Take the left fork for a lightly longer loop; you are now on Morton Bay Loop. This section has more uneven terrain, is slightly less travelled and more rugged, and goes down to water level.

At about 4.4km, Morton Bay Loop ends and connects with Cabin Trail; turn left and follow it for another 300m to the parking lot.

Rock Dunder is shown on some geological maps as a pluton. On others it is part of a much larger igneous feature termed Lyndhurst granite. But beyond definition, Rock Dunder is a remarkable formation of beautiful pink granite. It took form deep in the roots of the Grenville Mountains that a billion years ago towered over this part of Laurentia, now known as the Canadian Shield. Then, during the Ice Ages of the Pleistocene Epoch, which occurred within the last million years of our planet's history, Rock Dunder was under a solid sheet of slowly moving ice. That movement of ice did much to sculpt Rock Dunder's ancient and hard pink granite into its present shape on the Rideau Cataraqui landscape.