English: Looking northwest at Leon Johnson Hall on the campus of Montana State University in Bozeman, Montana.

There are two "Johnson Halls" on the MSU campus. One is A.J.M. Johnson Hall, and this one is not.

Leon Johnson Hall began construction in 1972 and was completed in 1976. It is named for Leon Johnson, MSU's seventh president. The eight-story building houses classrooms, labs, and offices. It has the second largest lecture hall on campus (it seats 225).

Leon Johnson Hall has had several problems since its construction. Beginning about 1988, bricks began falling off the building onto the sidewalks below. The north side of the structure was fenced off, as the university lacked the funds to repain the masonry. Flooding also affected the building, as the foundation proved leaky, the walls seeped whenever it rained or snowed, and the plumbing tended to leak. In 1997, the underground electric snow-melting system around Johnson Hall failed -- requiring a $40,000 replacement.

In 1999, cadaver lab used by pre-med students was moved from Lewis Hall to Johnson Hall at a cost of $150,000.

Since the mid-2000s, Leon Johnson Hall has seen major renovations. In 2005, $1.2 million was spent on a four-year project that completely removed the brickwork from the exterior and replaced it. The exterior brickwork was also reinforced to meet current earthquake codes, and insulation added to the exterior.

A major asbestos scare occurred at the building in 2010. Repeated plumbing leaks caused the ceiling tiles in the building to buckle, become stained, and sometimes collapse in sodden piles on the floor. The tiles began to be removed in October 2010, but by complete chance a worker on another building on campus noticed that the tiles were made of asbestos. The company doing the work on Leon Johnson Hall did not realize that the tiles were toxic. The building was evacuated for a week while testing was done to ensure the building had not become contaminated.

The following year, a $2 million renovation of the sixth floor occurred. The floor, which housed the Thermal Biology Institute, had not been renovated since the building's construction and was completely inadequate for current research needs. The original plan called for rearranging the interior configuration, adding fire suppression (sprinklers), upgrading electrical and HVAC, adding a cold room, and crafting heavy-duty cabinetry to accommodate autoclaves, boilers, and fume hoods. The sixth floor renovation was funded by a grant from the National Institutes of Health with money from the American Recovery and Reinvestment Act (the Obama stimulus). But because of tight cost controls, the project came in significantly under budget. Since all the grant had to be expended, the project was expanded to a complete rebuild of the sixth floor.

In 2012, a $4 million project to replace the entire HVAC system in Leon Johnson Hall began.

As of 2013, Leon Johnson Hall houses the Department of Cell Biology and Neuroscience, and parts of the Department of Plant Sciences & Plant Pathology and the Department of Environmental Science. The Washington, Wyoming, Alaska, Montana, and Idaho Medical Program (WWAMI) and the Health Professions Advising Office are also located there.