Governor Robert E. Smylie. This view from the foot of Capitol Blvd. looking across Capitol Park. Construction was started in 1906 and completed in 1920. The Capitol is 400 feet long, 225 feet wide and 200 feet to the top of the dome. It is faced with IDAHO GRANITE and the interior finished with Vermont marble, cost $2,290,000, Many interesting displays are on free exhibition.