seen as too high and in Project Rio Blanco the triple-blast rubble chimney structures disappointed the design engineers. Soon after that test the approximately 15-year Project Plowshare program funding dried up.In 2011, the United States Department of Energy reported that even after 25 years of gas production of all the natural gas deemed recoverable, only 15 to 40 percent of the investment could be recovered.

These early fracturing tests were later superseded by hydraulic fracturing