A plan to vastly expand a limestone mining operation on the northern edge of Glenwood Springs will set this Western Slope tourist town back a century, destroying its burgeoning tourist economy and clogging its streets with hundreds of trucks a day, critics say. Steve Beckley, owner of Iron Mountain Hot Springs, fears his business on the banks of the Colorado River could be ruined if mining activity alters how water flows and is heated deep beneath the earth’s surface on its way to the facility’s pools. His concerns are shared by his much older upriver competitor, Glenwood Hot Springs Lodge and Pool.