Project Rio Blanco

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title: "Project Rio Blanco" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["explosions-in-1973", "may-1973-in-the-united-states", "american-nuclear-weapons-testing", "american-nuclear-test-sites", "peaceful-nuclear-explosions", "rio-blanco-county,-colorado", "underground-nuclear-weapons-testing", "1973-in-colorado", "project-plowshare-nuclear-tests", "code-names"] description: "1973 underground nuclear test" topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/Project_Rio_Blanco" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary 1973 underground nuclear test ::

::data[format=table title="Infobox Nuclear weapons test"]

Field	Value
name	Project Rio Blanco
country	United States
test_series	Operation Toggle
Operation Plowshare
test_site	Rio Blanco Site,
date	May 17, 1973
test_type	Underground
yield	3x 33 kt
image	Rio Blanco Test Site.jpg
::

|name = Project Rio Blanco |country = United States |test_series = Operation Toggle Operation Plowshare |test_site = Rio Blanco Site, |date = May 17, 1973 |test_type = Underground |yield = 3x 33 kt |image=Rio Blanco Test Site.jpg|caption=Rio Blanco Test Site}}

Project Rio Blanco was an underground nuclear test that took place on May 17, 1973 in Rio Blanco County, Colorado, approximately 36 miles (58 km) northwest of Rifle.

Three 33-kiloton nuclear devices were detonated nearly simultaneously in a single emplacement well at depths of 5838 , below ground level. The tests were conducted in fine-grain, low-permeability sandstone lenses at the base of the Fort Union Formation and the upper portion of the Mesaverde Formation.

This was the third and final natural-gas-reservoir stimulation test in the Plowshare program, which was designed to develop peaceful uses for nuclear explosives. The two previous tests were Project Gasbuggy in New Mexico and Project Rulison in Colorado.

The United States Atomic Energy Commission conducted the test in partnership with CER Geonuclear Corporation and Continental Oil Company.

A placard, erected in 1976, now marks the site where the test was conducted. The site is accessible via a dirt road, Rio Blanco County Route 29.

Devices

As the creation of tritium was of greatest concern, the three devices used were specially designed to reduce tritium production, creating less than 0.2 g tritium each, primarily from the medium surrounding the devices. To reduce emplacement costs, the devices were very narrow in diameter, less than 200 mm wide.

References

References

1. United States Nuclear Tests, July 1945 through September 1992, [http://www.nv.doe.gov/library/publications/historical/DOENV_209_REV15.pdf DOE/NV--209-REV 15] {{webarchive. link. (June 15, 2010 , December 2000)
2. link. (February 9, 2022 , DOE Office of Legacy Management)
3. M. D. Nordyke. (26 July 2000). "The Soviet Program for Peaceful Uses of Nuclear Explosions". Lawrence Livermore National Lab.

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