  We argue for a cost-effective, long-term North American underground science
strategy based on partnership with Canada and initial construction of a modest
U.S. Stage I laboratory designed to complement SNOLab. We show, by reviewing
the requirements of detectors now in the R&D phase, that SNOLab and a properly
designed U.S. Stage I facility would be capable of meeting the needs of North
America's next wave of underground experiments. We discuss one opportunity for
creating a Stage I laboratory, the Pioneer tunnel in Washington State, a site
that could be developed to provide dedicated, clean, horizontal access. This
unused tunnel, part of the deepest (1040 m) tunnel system in the U.S., would
allow the U.S. to establish, at low risk and low cost, a laboratory at a depth
(2.12 km.w.e., or kilometers of water equivalent) quite similar to that of the
Japanese laboratory Kamioka (2.04 km.w.e.). We describe studies of cosmic ray
attenuation important to properly locating such a laboratory, and the tunnel
improvements that would be required to produce an optimal Stage I facility. We
also discuss possibilities for far-future Stage II (3.62 km.w.e.) and Stage III
(5.00 km.w.e.) developments at the Pioneer tunnel, should future North American
needs for deep space exceed that available at SNOLab.
