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

A 2024 joint submission to the Colorado State Board of Health calls for renewed scrutiny of Rocky Flats, including independent review, air monitoring, additional health research and greater public disclosure.

In March 2025, the Town of Lyons added its voice to growing local-government opposition to the Rocky Mountain Greenway trail connection through the Rocky Flats National Wildlife Refuge. On March 17, the Lyons Board of Trustees voted 6–1 to oppose construction of the Greenway through the refuge and its connection to regional trails. Lyons joined Broomfield, Superior and Westminster, which had previously withdrawn their support for the project. The Rocky Mountain Greenway is en