Until 1885, public medical care occurred at several locations and via multiple funding mechanisms, including a "Poor Farm" where people grew their own food.

[4] Expansion of the building occurred in the early 1890s and again in 1899, when architect Charles S. Haire designed new wings.

[2] The original hospital structure was destroyed on October 18, 1935, when a major earthquake struck Helena.

The Helena office of J. G. Link & Company[5] were the architects of this Art Deco/Early Moderne design, which includes a flat roof, colored concrete, and diamond-shaped tiles.

[2] Dr. Cooney, in whose honor the hospital was renamed and the street was named, began working there in the 1920s and served as administrator until the 1950s.

[2] In 1984, the Cooney Convalescent Home moved to a new location on the other side of Helena, near St. Peter's Hospital,[3] and the building was converted to office space, mostly occupied by various healthcare practitioners.

[2] The shed is a small, rectangular one-story concrete building between the west and north wings.

The ambulance garage is a brick rectangular structure built in 1900 on a raised concrete foundation.