露天掘り
The first coal mines in the Twomile Run watershed were deep mines, but there are no surviving maps of them. Surface mining of the Lower Kittanning and Upper Kittanning coals began after World War II, with the Lower Kittanning coal being mined to a depth of . By the 1970s, the surface mining had ended. Much of the coal mined in the entire Kettle Creek watershed was in the Twomile Run watershed.