I own property abutting a abandoned railway bed. Part of the…

Hello:
This will depend on which land system the property is held under. Most (over 95 per cent) of land in the province is now subject to the land titles system. That system has abolished any rights arising from use or possession of the land, and in that case you would only have a right to neighboring property if you get an agreement with the landowner, or had an easement registered on title. Prior use of the property would not create any legal rights to that property.
If you do not know if the land is subject to the land tilde system, you can have a search done through many online services, which are quite inexpensive. If the title is found for the property, then it is subject to the land titles system.
If no title has been issued, then the land would still be subject to the older land registry system. In that case, you would likely want to speak with a lawyer who can look carefully at the registry documents. In that case, having had use of the land for over 20 years you could have established a prescriptive easement, which means that you would be allowed to continued use of the land. But I would recommend that you speak in person with a lawyer in that case.
I hope this is helpful. If you have no further questions, please rate the answer positively, as otherwise the site does not credit me, even if you have paid a deposit. You can still ask follow up questions after rating though, if you wish.