Depth, access and a $115 million package of local support have made the Homestake gold mine in Lead a top candidate for a national underground laboratory.
Minnesota's Soudan Underground Laboratory is already doing science, and the Institute for Underground Science in Minnesota plan would support labs at other sites.
The Henderson molybdenum mine west of Denver, Colo., is still operating, so infrastructure and mine technicians are in place for a quick start-up.
The unused Pioneer Tunnel, behind the trees to the left of the Cascade Railrad Tunnel (below), offers horizontal access and doorstep rail delivery of equipment.
Check back soon for updates as our coverage continues and includes the other candidate mines.