You need to find the owner. If it is OK, he/she will tell you so. If not, he/she will tell you so. To find the owner, contact your county courthouse. Or, you might even be able to find plat books online for your area. Or buy a current plat book for the area.
Years back a farmer assured me his neighbor would not mind me hunting his land. So, to be sure, I found the neighbor and asked. The answer was a very firm "No".