When Muskoka was first surveyed in the late 1800's, the surveyors in their wisdom, allocated a 66' wide strip at the shore of the lakes for a road allowance. This piece of land was deeded to the Crown and subsequently to the Province. However, in very few instances was an actual road built along these shore road allowances (SRA).
As time went by, the shorelines of the lakes were subdivided for cottage lots. Technically however these lots only extended to within 66' of the high water mark (the width of the SRA). Later it became apparent that the SRA's were never going to be used for roads so eventually the Province started to sell them to the cottage owners abutting them. Subsequently, the SRA's were transferred to the Municipalities to administer.
What are the pros and cons of owning a property where the SRA is not closed (ie. still owned by the Province) and in this instance, why would you want to purchase it? One argument may be that your existing cottage encroaches on the SRA and as such you can't put a mortgage on it. Or, you are planning an addition to your cottage and you need more property to be within the gross allowable square foot limit under the building bylaws.
On the other hand, if these aren't factors, why bother? It can never be used as a road as it isn't continuous allowance as more and more abutting property owners bought their SRA. Although technically it is "public land", nobody knows whether you own it or not so people aren't likely to come ashore for a picnic. The fact is, whether you own it or not, you have the right (with the requisite permits) to build a dock at the shore. In some instances owning the SRA could increase your shoreline length if your shoreline is convex in shape (ie a point of land). This may as a consequence have the effect of increasing your tax base.
The foregoing is a brief summary of shore road allowances. This subject should be discussed in more depth with your lawyer if you are considering the purchase of the SRA abutting your property or if a cottage you are considering purchasing does not include the SRA.