PICHER, Oklahoma (CNN)-- Wearing powder blue pants ... one called out. Gray mountains of toxic gravel loomed behind the school, just out of sight, as Hoppy hobbled past a bundle of balloons ...

Starting in the late 19th century, Picher was at the forefront of Oklahoma’s lead and zinc ... The chat piles – mountains of crushed limestone, dolomite and silica-laden sedimentary rock ...

PICHER, Oklahoma (CNN)-- Wearing powder blue pants ... one called out. Gray mountains of toxic gravel loomed behind the school, just out of sight, as Hoppy hobbled past a bundle of balloons ...