if and where you can get a key for a gate depends on who owns the gate and if they want to let you behind it. Some are Foresty and you would get the key from the local forestry office, some are put up by the logging companies, and you can get the key from them, and some are put up by natives, and you can get a key from them. Most keys will open a few gates, but you have to figure out which ones they work for. They don't usually telll you. You usually have to leave a deposit for the key when you get it.