 As housing prices in the Bay Area increased in the late 20th century, Middletown and nearby Hidden Valley Lake enjoyed a population boom as commuters moved to the Middletown area looking for affordable housing; keeping their jobs 50 to 100 miles away in Santa Rosa, Napa, and San Francisco.Middletown is currently populated primarily by commuters and retirees, enjoying a modest tourist trade based primarily on Harbin Hot Springs and the Twin Pine Casino located on the local Rancheria south of the town.On September 12, 2015, about half the town, including city blocks, commercial buildings and an apartment complex, was destroyed by the fast-moving Valley Fire.