The National Science Foundation established a multi-tiered path to DUSEL, involving a series of "solicitations" (S1, S2, S3, S4, etc.) and a series of three "design reports":
Conceptual Design Reports (CDRs)
Scientific collaborations representing eight proposed DUSEL sites created CDRs in 2006. (The field was narrowed to four finalists in 2007.) Each CDR made the case for a particular site. The NSF chose Homestake from among those sites on July 19, 2007.
Preliminary Design Report
The National Science Foundation provided funds to the University of California at Berkeley to create a Preliminary Design Report (PDR) to guide the final design and construction of the Deep Underground Science and Engineering Laboratory (DUSEL) at the former Homestake gold mine in Lead, South Dakota. The PDR also was created to prepare DUSEL for consideration by the National Science Board for inclusion in the Major Research Equipment and Facilities Construction (MREFC) program in 2011.
In December 2010 the National Science Board declined DUSEL funding for MREFC. However, the DUSEL Collaboration delivered the completed PDR to the NSF in June 2011. Going forward, the PDR can serve as the encyclopedia of data, designs and analyses for constructing laboratories underground at Homestake.