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Lomond Sinkhole

Lomond, Bonne Bay

Located in the backcountry of the islands west coast, is a 30 metres deep, 45 metres wide sinkhole. A small brook flows off the top of the hole and falls nearly 100 feet to the bottom before disappearing into the rocks below. If Newfoundland had a list of natural wonders, the Lomond Sinkhole would surely be high on the list. This unique feature formed when the roof of a large underground cave collapsed. Over the last several years the Sinkhole has become a very popular spot for snowmobilers and off-road enthusiast. 


Sinkholes form when weak, underground carbonate rock (commonly limestone) erodes leaving behind a cave. When the roof of these caves become too heavy for the walls to support it, the roof collapses leaving behind a large hole/depression in the ground. In the backcountry of western Newfoundland, most of the surface water lies stagnant in ponds and bogs. These environments cause the water to gain a high acid content.

The Lomond Sinkhole formed when acidic water seeped through a vertical fault, dissolving a weak layer of limestone located deep underground below a strong layer of slate. This caused a cave to form in the limestone. Over many years the caves roof became more and more unstable until it finally collapsed leaving behind this large hole.

The sink hole is located on a small ATV trail that is marked by a descriptive sign put in place by Corner Brook Pulp and Paper Ltd. The sign describes the holes formation and a history of logging in the area. A steep path and guide rope help those who want to descend into the hole. 

Logging History

In the hole, aside from rock, and moss you'll see large slabs of cut wood. These are from a portable mill that was used in the area when it was first logged in 1957. It was logged by Cyril Goosney for Bowaters Newfoundland Pulp and Paper Mills Ltd. Since then the area has been cut over twice by Corner Brook Pulp and Paper Ltd (CBPP). On their most recent cut in 2010, CBPP left 20 meters of forest surrounding the hole as a safety zone.

Getting There

There are several ways to get to the sinkhole. By snowmobile it is located just off a marked snowmobile trail behind Big Bonne Bay Pond. As of summer 2014 the logging road into the area was in good shape and even drivable in car.  

Because of an increasing popularity in the sinkhole, many signs have been placed on the roads around the area to help people find their way.

The Other Sinkhole

On the other side of Lomond off a small, overgrown logging road is another sinkhole. The hole is not nearly as large in diameter as the other one but is just as deep or arguably deeper that the one above. Its small diameter and large depth makes this one scarier to be around because there is no easy way up or down into it due to vertical cliffs on all sides. For many years locals believed this to be the only sinkhole here. It wasn't until Bowaters began logging there inn recent years that they learned about the one above.  

I was speaking to some locals familiar with the area during my visit who told me stories of how they use to through slabs of old wood into this hole and later the spring, during the snow run off, they would see the slabs flowing down the Lomond River. This would suggest that there is quite a large passage between the bottom of the hole and the Lomond River located nearly 1.5 - 2 kilometers away. 

I have also heard stories that loggers use to throw horses bodies down into the hole if the horse would become injured or pass away while in the area. I've even heard some say you can still find their bones and skeletons at the bottom of the hole. 

Coordinates of the sinkhole:

49.390735 N

57.766721 W

It seems only locals around Bonne Bay and surrounding area know about this sinkhole and although it's located right off a popular snowmobile trail it is easy to miss because of its small circumference. I wasn't in the area long but plan to return and hopefully descend into the hole and see what is down there. I would also like to explore the area to see if there are any more large holes around. 

Surrounding Area

Sinkholes are a type of karst topography. This is geology lingo for features created by eroded carbonate rocks (ie. Limestone). Karst features such as sinkholes are rarely ever isolated features. They are normally part of a greater landscape that has been influenced by the presence of these weak rocks. The Lomond Sinkhole is no different. The area surrounding the sinkhole south of Bonne Bay, west of Deer Lake, and North of the Bay of Islands is littered with fascinating features formed by the erosion of carbonate rock and more specifically, limestone. The area has some of Newfoundland's most breath taking scenery and some of its most hidden geologic features. 


The limestone of the area dates back to the Ordovician period (485 to 443 million years ago). 

In the area there are several large underground drainage basins from which many of the ponds and rivers drain from. Many of the large brooks and rivers around have their beginnings from small springs. 


The Caves and the 'Reappearing' River at Indian Dock Pond

This brook flows into Indian Dock Pond about 22 km in Incinerator Road, North of Deer Lake. The brook slowly disappears as you walk upstream. Walking a little farther up the river bed the bed seems to just disappear into a steep hillside. This is believed to be once an entrance to a series of caves that go under the hill. A recent rock slide blocks off any chance of following the river into the mountain. However on a hot day in the summer, if you stand next to the hillside, you'll notice a cool air being pushed out between the fallen rocks. This is evidence that behind those fallen rocks is indeed an air filled cavern. 

Many large sink holes can be found in the area, however most of these have been filled with water making it look like a pond. Geologist believe there is a large networks of caves beneath the area but up until now there has been no entrance found that is large enough for people to get through.  

The same forces and rock types that created the Lomond Sinkhole are also responsible for creating the Corner Brook Cave System. 

Sources & Further Exploring

Corner Brook Pulp and Paper Ltd. (n.d.). Lomond Sinkhole. Found at

Karolyi, M. (1978). Karst Development in Ordovician Carbonates: Western Platform of Newfoundland (Master’s thesis, McMaster University). Accessed through the Centre for Newfoundland Studies.

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