Mohun Lake runs about 10 km south to north. The lake is doubly named on some maps with the northern 1/4 called Goose Lake. I have seen this on the popular Vancouver Island BC Backroad Mapbook which is one of the most common map resources people use for the canoe route.
The Mohun Lake Campground is located just off of the Menzies Bay Mainline. Launching from there it is a short paddle to the island in Mohun Lake. This island has one well marked campsite on the southwest corner. We had planned to camp at that location but someone was already there. We paddled around the island to find a different location. We did find a good spot in the woods off of the northeast bay on the island. The location is not obvious from the water, but once we walked into the woods 10 metres we had a location where we had no trouble having all nine of us camp, though this location was not appropriate for a campfire.
Mohun Lake does have a moderate amount of motorized boating on it. This is not only people fishing, but also waterskiiing, tubing and kneeboarding.
On the eastern shore of Mohun lake between the island and Morton Lake provincial park there are two nice beaches that can easily be used for camping. The one about 3 km up the lake had an outhouse. With higher water the beaches may not have as much space for camping.
As you canoe northwards, do not take the first channel you see on the eastside at Morton Lake park, keep going another 200 metres north to the boat launch.
Going north on the lake is Morton Lake Provincial Park. This park has an attendant from the start of May to Oct 15th. Camping here costs money as it is provincial park. There is a nice boat launch on the northern end of the park that accesses Mohun Lake. Morton Lake is a popular local swimming location and will be busy in the summer months with day trippers. The campground can also be full and I suspect if you want to use it in the summer you should consider reserving your spot.
The Morton Lake boat launch area offers you tables to eat at, fresh water, garbage drop off and good outhouses.
North of Morton Lake you will see a drop off of motorized boating. About 1.2 km north you come to a narrows that has several old trestles of logging railways spanning over the lake. Only the supports remain.
As a quick aside, historically the region was criss crossed with hundreds of kilometres of logging railways. You can still see evidence of them throughout the area in the form of trestle remains or roads that maintain consistent grades over long distances. The Mohun Lake West forest service road is one example of an old railway bed.
North of the trestle the lake becomes much quieter and much more of a wilderness experience. this is the segment known as Goose Lake on some maps.
There are a number of campsites around the trestles and there are several small islands just to the north of here that also offer locations where you could camp.
At the north end of Mohun Lake is the start of the portage to Twin Lake. There is a camp site here with a fire circle and an outhouse. We chose not to camp here because there was a lot of broken glass here. The site has no beach and has a dirt bank you have to pull your canoe up.
This location is about 1.6 km from highway #19 via the Goose Lake Forest Service Road. I expect that this explains the broken beer bottles. It also makes this a good location to get help if there is a problem.