Potential coverage for this situation varies from policy to policy so read your policy carefully. Many home insurance agents in Oklahoma give the wrong answer on this question.
Most quality home insurance policies in Oklahoma will extend the Liability Coverage from your Oklahoma home insurance to vacant property that is not being farmed. What is vacant? Is usually means absolutely no structure, no improvements. Some companies allow a fence. Therefore, if there is any farming or if there are any structures, you usually need a separate policy for this property.