The discovery of Rocky Flats-derived plutonium in air-filter samples collected along Indiana Street has renewed concerns about plans to expand the Rocky Mountain Greenway trail system near the former nuclear weapons plant. The Rocky Mountain Greenway Project began in 2016 as an effort to connect three national wildlife refuges—Rocky Mountain Arsenal, Two Ponds and Rocky Flats—through a regional trail network. Plans include an underpass connecting the Rocky Flats National Wild