Facts about the Idaho Capitol Building

In 1905, the Idaho legislature passed the bill authorizing construction of the Capitol Building.
The architects of the Capitol Building were J.E. Tourtellotte and Charles Hummel.
The dome and central parts of the Capitol were built first—from 1905-1912.
The wings (House and Senate chambers) were constructed during 1919 and 1920.
Most of the superstructure is made of sandstone taken from Table Rock (near Boise).
Convicts from the old Idaho Penitentiary were responsible for transporting the 10-ton sandstone blocks from the quarry.
Four types of marble were used for the Capitol’s interior:
- red from Georgia
- gray from Alaska
- green from Vermont
- black from Italy
From the first floor to the eagle atop the dome, the Idaho Capitol Building rises 208 feet. See a diagram of the capitol dome.
The floor area of the building when completed was 201,720 square feet.
Over 50,000 square feet of artistically-carved marble exists in the building.
The original cost to construct the Capitol was $2.1 million.
Replacement costs today would be over $100 million with many materials considered irreplaceable.
Idaho’s Capitol Building is the only one in the United States heated by geothermal water. The hot water is tapped and pumped from a source 3,000 feet underground.
The eagle atop the dome stands 5 feet 7 inches and is made of copper. In 2005, as part of the exterior restoration, it received a new gilding of gold leaf.

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