The tape can be found inside Gauley Mine, headed south down the tracks in the station directly across the T-intersection.
Greg Harris: Ok gang, the boss wanted me to leave you some instructions... since you apparently can't run this mine without me holding your hands. We're gonna light this place up today. The holes are drilled, so just get the dynamite packed in and wired up. Make sure everyone's a safe distance this time. Tommy, you DO NOT TOUCH the plungers, got it? You're the reason we're down two guys this month. Carl, you're in charge... Don't fuck this up.