Project Rulison

Project Rulison, named after the rural community of Rulison, Colorado, was a 40-kiloton nuclear test project in the United States on September 10, 1969, about 8 mi SE of the town of Grand Valley, Colorado (now named Parachute, Colorado) near western Colorado's Grand Valley in Garfield County. The location of "Surface Ground Zero" is 39.40528°N, -107.94853°W. It was part of the Operation Mandrel weapons test series under the name Mandrel Rulison, as well as the Operation Plowshare project which explored peaceful engineering uses of nuclear explosions. The peaceful aim of Project Rulison was to determine if natural gas could be easily liberated from underground regions.

The test succeeded in liberating large quantities of natural gas however the resulting radioactivity left the gas contaminated and unsuitable for applications such as cooking and heating homes. Although projected public radiation exposures from commercial use of stimulated gas had been reduced to less than 1% of background, it became clear in the early 1970s that public acceptance within the U.S. of any product containing radioactivity, no matter how minimal, was difficult if not impossible. The Department of Energy began a cleanup of the site in the 1970s which was completed in 1998. A buffer zone put in place by the state of Colorado still exists around the site. A January 2005 report by the DOE stated that radioactivity levels were normal at the surface and in groundwater, though a later report due in 2007 is expected to more fully explore if there is subsurface contamination and whether or not radioactivity is still spreading outward from the blast site itself.

The Houston, Texas-based company Presco is seeking to drill for natural gas within the buffer zone as of June 2005, putting in as many as four wells. The company had initially received approval to drill one well, but the county dropped its support when more extensive plans were revealed.

This was the second of three natural-gas-reservoir stimulation test in the Plowshare program. The other two were Project Gasbuggy and Project Rio Blanco.

A placard, erected in 1976, now marks the site where the blast took place. It is accessible via a gravel road, Garfield County Route 338.