From ArborWiki

The Map Library is the principal collection for cartographic materials at the University of Michigan. It also provides assistance with geographical information systems, statistical software, and relevant data through Numeric & Spatial Data Services in a laboratory in the Map Library.

Open from 10 am - 5 pm, Monday - Friday year-round, and Sundays from 1 - 4 pm during Fall and Winter semesters.

Find out more at http://www.lib.umich.edu/maplib/