Built around 1900, the Heritage House has stood at the center of historical horse racing activities in the Livermore–Amador Valley for more than 90 years. It is the only remaining structure from the era of the privately owned racing business that had been important to the local economy since the mid-1800s. The adjoining track is the oldest one still in operation in the United States. Rodney G. Mackenzie entertained many Canadian and American harness racers who wintered their horses there, and he helped form the Alameda County Fair Association and the first Alameda County Fair in 1912.