By the late 1960s Palmer was operating one underground coal mine on the east bank of the Green River and had recently closed another. The active mine was called the No. 10, named after one of the seventeen coal seams of the Franklin series. The No. 12 mine had closed several years earlier. A wooden bridge with narrow gauge rails for small coal cars crossed the river and provided access to the west side where flatter ground made coal removal by dump-trucks easier. In March 1971, Rocket Research using special explosives blasted the old bridge down. The ceremony was attended by many State and local dignitaries as well as television crews from NBC for the monthly documentary program called "First Tuesday" shown in May of that year.