The library uses the Library of Congress Classification system to organize books in the stacks by subject. This means that it is easy to browse the stacks once you know the subject heading and call number associated with your topic.
At McQuade, call numbers A-H are located on the 2nd floor & J-Z are located on the 3rd floor.
| Subject | Call Number |
| Natural History (General) |
QH1 - QH78.5 |
| Biology -- General |
QH301 - QH705.5 |
| Biology -- Genetics | QH426 - QH470 |
| Biology -- Ecology | QH540 - QH549.5 |
| Botany | QK1 - QK989 |
| Zoology | QL1 - QL991 |
| Human Anatomy | QM1 - QM695 |
| Physiology | QP1 - QP981 |
| Microbiology | QR1 - QR502 |