The Underwood Tunnel's purpose was to drain the mine at the Pennsylvania Coal Company's #1 Colliery which was located at the present day Keystone Landfill. The PA Coal Company mined the beds to the northwest of the Eddy Creek Colliery. This tunnel was designed to drain the mine that sat above 700 feet above sea level. It did this by gravity, because it sloped towards the river and no pumps were needed. It also drained pumped water from below that level. Construction began in 1903 and the tunnel was completed August 30th 1906. The PA tunnel spans a distance of 6,500 feet and construction was done from both ends, the #1 Colliery in Dunmore and the end at the Lackawanna River (which is where we entered). The Tunnel was eventually divided between the #1 Colliery and the Underwood also operaten by the Pennsylvania Coal Co. The first 1200 feet is brick lined and measures eight by six feet. 1201 to 6200 measures fifteen feet by seven feet. The rest of the tunnel is eight by six feet.