From ArborWiki

Mosher-Jordan, or "MoJo", is one of the Hill Dorms. It is on Observatory Street. MoJo houses only a few hundred students, and is small enough that meals are not served on weekends.

The third floor houses the "UROP in Residence" (Undergraduate Research Opportunities Program) members, and the Fifth Floor houses members of the Women in Science and Engineering Program (WISE). MoJo is being renovated 2006-8 (or 2007?), so WISE has moved to East Quad, joining the Residential College.