A Nevada manganese mine that left arsenic and lead in the ground is undergoing an estimated $257 million cleanup; a 3.5-acre park has now opened on the former site, with more than 3,000 homes planned nearby

• In Henderson, Nevada, a former manganese mine that operated for decades and left behind contamination is being transformed into a large residential community.
• The opening of Greenbow Park marks a new phase in that redevelopment.