Built in 1879, the building housed J.J. Elliott's assay office. During the boom days of the 1880's, dozens of ore wagons were often parked on Miner Street in front of the Exchange. Elliott promoted himself in city directories as an assayer and bullion buyer, and he was also president and manager of the Idaho Springs Electric Company, where he had the difficult job of convincing the citizens of Idaho Springs that electricity was safe and not just a passing fad.