Lewis Hall houses the Ecology, Computational Biology and Microbiology Departments.
Built in 1923, it is named for Meriwether Lewis, co-leader of the Lewis and Clark expedition, 1804-06. Just inside the south entrance door are two murals painted by MSU art students in 1942 as well as fish and wildlife displays on the second and fourth floors. The mural on the east wall shows prehistoric Montana. The mural on the west wall depicts the fight against rocky mountain spotted fever in Montana and is dedicated to two MSU students who died while studying the disease. It is home to the University Vertebrate Museum and Herbarium. Both the Fish and Wildlife Management Program Center and the Montana Cooperative Fishery Research Unit are placed here as part of the Department of Ecology. This building currently has no handicap access.