what geographic feature would escaping enslaved people need to cross to gain their freedom on the Underground Railroad?

To gain their freedom on the Underground Railroad, escaping enslaved people would often need to cross various geographic features. One prominent geographic feature they would often encounter is rivers or bodies of water. These water bodies posed significant obstacles as they needed to be crossed to continue their journey towards freedom. Several major rivers, such as the Ohio River or the Mississippi River, presented formidable challenges. Crossing these rivers required careful planning and often involved the assistance of skilled guides or conductors who knew safe crossing points or provided boats for transport.