For sure - it happens lots. The land use maps are only so useful. we have areas that are a patchwork of private and public land, and nobody really bothers to get surveys done unless they're subdividing/severing their lot. Boundary trails, and even public concession roads weave in and out of and across private property everywhere in my neck of the woods. You have two choices: Put up signs or live with it.I could see that happening depending on where you live, sometimes mistakes happen depending on the geography. In Southern Ontario for example there is almost zero chance of ending up in a bush lot on a farm by accident. In parts of Northern Ontario without a land use map I could see that happening quite easily.