[2] In September 1961, the Soviet Union resumed nuclear testing — including the test of the most powerful nuclear device ever designed, the Tsar Bomba, in October — and the United States followed suit with Operation Nougat.

The Tamalpais test was conducted in the U12b.02 adit of Rainier Mesa by Lawrence Radiation Laboratory on October 8, 1958.

[3] The shot took place in a 394-foot-long hook-shaped drift ending in an unusually large test chamber lined with salt blocks as part of an experiment in preparation for Project Gnome.

[5][8]: 421–423 Adams was planned to be the final test of Hardtack II, but due to unfavorable winds the shot was never fired.

The shot was intended to be a balloon test, and had been fully assembled and raised to firing altitude when it was cancelled.