About our Restoration and Addition Project

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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    Commission Meetings
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      Meeting dates, times, and locations are subject to change.