New Warning Signs Coming to Colorado's Atomic Bomb Factory

Rocky Flats Plant, a former nuclear weapons production facility, will get new signage to caution visitors about the site's hazardous history.

Published on Mar. 2, 2026

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For 40 years, the Rocky Flats Plant near Denver manufactured nuclear weapons parts and plutonium pits, a key component of atomic bombs. After the plant was shut down in 1992 and a $7 billion cleanup project, the area was designated as a wildlife refuge. However, due to ongoing concerns from nearby residents and an increase in hikers visiting the site, new warning signs are being erected to inform the public about the facility's hazardous past.

Why it matters

Rocky Flats has long been a controversial site in Colorado due to its history of nuclear weapons production and environmental contamination. The new warning signs aim to educate the public about the risks and history of the former plant as it transitions to a wildlife refuge, addressing lingering community concerns about the site's safety.

The details

The new warning signs will be bright yellow and feature headlines such as 'The Rocky Flats Plant leaded plutonium and hazardous materials onto the land and into the water' and 'After years of hazardous waste removal, Rocky Flats was designated as a wildlife refuge.' The signs will provide further details about the plant's history and encourage hikers, bikers, and equestrians to 'make informed decisions before entering the refuge'.

  • Rocky Flats Plant operated from 1952 to 1992.
  • The FBI raided the Rocky Flats Plant in 1989.
  • A $7 billion cleanup project at Rocky Flats was conducted in 2005.
  • Rocky Flats was designated as a wildlife refuge after the cleanup.

The players

Rocky Flats Plant

A former nuclear weapons production facility located near the Denver suburb of Arvada, Colorado that operated for 40 years until its closure in 1992.

Two Ponds National Wildlife Refuge

A wildlife refuge located near Rocky Flats in the Denver area.

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What’s next

The new warning signs are set to be erected at the Rocky Flats wildlife refuge in the coming months.

The takeaway

The new signage at Rocky Flats aims to educate the public about the site's hazardous past as a nuclear weapons production facility and address ongoing community concerns about the safety of the wildlife refuge, which was established after a costly cleanup project.