Sun over Blackwater National Wildife Refuge, Dorchester county, Maryland photograph in black and white, infrared. Harriet Tubman used this area as part of her escape route to free area slaves.Blackwater Refuge was part of the Underground Railroad in the 1800’s for slaves escaping from southern plantations to their freedom in the North. Harriett Tubman helped dozens of slaves escape to their freedom via the waterways of Blackwater Refuge. You can still feel Harriett’s courageous spirit when you visit this area.