Beyond the sumped and flooded entry to the Mulu Section, a beautiful trunk passage leads deeper in. North Bore extends for many thousands of feet towards the ridges of North Breckinridge County. One stretch of this trunk, a segment of which is illuminated here, runs for nearly 500 feet straight as an arrow. In this image, explorers Hutchinson and Tobin provide background illumination with two GE M-3 flashbulbs. Foreground illumination was provided by two slaved T-32 electronic flashes. Camera was activated with IR remote.