enterprise. It could also help ensure access to underground space for experiments led by U.S. scientists, who have historically been leaders in underground science. At the same time, it would guarantee the United States a leadership role in the expanding global underground science community while being a principal component of the growing U.S. world-class particle physics program at the Intensity Frontier.

Conclusion: Development of an underground research facility in the United States would supplement and complement underground laboratories around the world. A U.S. facility could build upon the unique position of the United States that would allow it to develop a long-baseline neutrino experiment using intense beams from Fermilab. It could accommodate one of the large direct detection dark matter experiments and one of the large neutrinoless double-beta decay experiments that are needed by the international effort to delve into these critical scientific issues, while sharing infrastructure among the three experiments, which are of comparable import. It could also host and share infrastructure with other underground physics experiments, such as an accelerator to study nuclear astrophysics, and with underground experiments in other fields. An underground research facility would benefit the U.S. research communities and would guarantee the United States a leadership role in the expanding global field of underground science.