In October 2025 we explored Historical Zone H20 (Bonnechere River Camboose Camp), and made plans back then to try reach the Prong Lake Bridge site, Historical Zone H19.


Historical zones as presented in the Algonquin Park Management Plan Amendment, 2013, Appendix C; Figure 3b, page 17.

Algonquin Provincial Park Archives & Collections, D-2-3-4b, Mountain and Hutchinson. Used with permission.

There seem to be very few historical records describing the Prong Lake Bridge, but the Collections Coordinator at the Algonquin Park Archives was able to locate this aerial photo from the 1970s showing what remained of the bridge at that time. 

Water flows out of the lake into Fairy Creek, which is visible on the left side of the image.Algonquin Provincial Park Archives & Collections, 1976.25.6, C.A.G. Matthews. Used with permission.

From what can be seen in the Prong Lake photo, that bridge was of a quite different construction style than the bridge pictured above — the Canoe Lake Mill, showing the bridge over Potter Creek. That bridge used timber pilings and wooden spans for support. Today only remnants of that bridge remain.


The Prong Lake bridge appears to have been built using log cribs. Constructed by stacking unhewn or heavy squared logs into rectangular boxes, the hollow vertical cells or “cribs” would be filled with stone and rock ballast to anchor the structure against spring ice and water currents. Long logs would stretch across the cribs, spanning the waterbody, with a wooden deck laid on top. 

One article I read indicated that this type of construction was intended for rapid assembly and was not intended to provide a permanent structure. As a result, such log crossings were prone to rot and to being washed out over time. Our hope was that at least some of the structure, and perhaps some of the cribs, might still be visible today.

Map of Algonquin Park, Dr. Bell’s Map, 1908

This map reveals that Prong Lake was originally named Prong Horn Lake. It also shows there was an early logging road running from Shirley Lake to the Bonnechere River. That road appears to have passed approximately one kilometre below Prong Lake.

In planning a route to Prong Lake we considered using the same hiking route we had used to reach the Bonnechere Camboose camp zone, which would have involved hiking to the top of the Bonnechere River, travelling west to cross Fairy Creek and then down to Prong Lake.


Instead, we opted to travel as far as possible on an old logging road toward Redpole Lake. While that would take us a good distance north of Prong, it would mean less bushwhacking through dense bush.



We were hiking during prime raspberry season and stopped at this spot to sample a few. From the way plants were trampled down and the amount of bear scat around it was clear the bears were making the most of the berries as well.



Looks like raspberries are the primary food for the bears at this time in August.


We made it to Fairy Creek. At one time there was a wooden bridge over the creek, just above this point.


We looked for a narrow, shallow place to cross the creek.

We approached Prong Lake from the east, and after crossing a marshy area we came to the top of Prong Lake close to the bridge site.


This short point of land marks the eastern end of the bridge. The logs in the water correspond to the spans visible in the photo from the 1970s.






We had downloaded aerial photos from the 1940s, as well as other files, and used them once on the site to get a better sense of the outline of the bridge and how it was constructed.


From where we stood we could see that logs and beams had drifted from their original position toward Fairy Creek.


I made my way across the logs to have a closer look.


It is clear unhewn logs were used in building the bridge. Some of the logs are incredibly long.


Notches on some of the logs suggest how they were interlocked.


Looking across to the far shore — logs are visible.


The log in this image provides a sense of the length of the logs used to span the cribs. We could see some structure in the water in front of this longer log, but not having a canoe we could not get close enough to determine if this is the remains of one of the cribs.


In addition to beams visible on the surface, other timbers lying on the bottom have been preserved.


One of several mysteries associated with the bridge is this — where would a road from the bridge be going? On the eastern side of the bridge the land rises sharply from the shoreline. Fairy Creek flows across the north side of the lake, and there is wet, boggy land to the east. The angle of the bridge suggests a road from the bridge would have to have run along the hillside shown in the image above.



It does appear a narrow road had been cut into the hillside, running south above the shoreline of the lake. We had heard from several sources that in addition to the bridge at Prong Lake there may have been a mill or camp of some type. We decided to make our way down the lake in the hope the outline of the road might lead to remnants of a mill.

Looking south on Prong Lake.

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About half way down the lake we came to Hidden Creek. The faint outline of a road leads to this point. Here, too, there are logs in the water and along the shoreline which suggests a small bridge may have been constructed here as well. Unfortunately, the width of the creek and the wetland surrounding it prevented us from proceeding further. 

Considering there was a logging road not too far south of Prong (as revealed in the Bell map of 1908), it is possible that a road did run south from the Prong Lake Bridge along the narrow high land along the shoreline and then across to the logging road. But that would require more research to determine.



On our way back to the bridge site my brother took photos of the numerous mushrooms and flowers along the lake.


Bottle Gentian growing along the shore of the lake. Photos of some of the mushrooms observed during the hike are presented at the end of the report.



After leaving the bridge site we explored areas east of Prong in the hope of finding some sign of a mill or camp. We did come across areas that had been logged in the not too distant past, but no indication of a mill.



On the return journey, about 600 meters east of Redpole Lake, we came across this abandoned canoe. The canoe has been sitting in this location long enough that the accumulated debris had composted sufficiently for a tall growth of grass to get established.


The metal plate in the bow of the canoe indicates it was built in 1977.


Algonquin Provincial Park Archives & Collections, 1992.3.29, S.R. Gage. Used with permission.

On our way out of the park we decided to stop at Basin Depot to look at the condition of a building there that was usually referred to as the “garage”. The culverts shown in this photo from 1984 have been replaced by a bridge. The photo shows the building was located quite close to the road.


Despite being just off to the side of the road, today the building is almost totally obscured by trees and brush. While the roof caved in decades ago, some of the log walls are in surprisingly good shape. The following photos provide a sense of its current condition.







Conclusion — while very little remains of the Prong Lake Bridge, what does remain provides a feeling for the effort that would have been involved in building such a structure. As to the date of construction, and whether there was a logging camp or mill at the lake, those details remain something of a mystery.


Our route — 29.08 km

This report, and the index of our other trip reports can be found at the following link.
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