Keystone is located in east Iowa. Keystone is part of Benton County. Keystone has 0.45 square miles of land area and has no water area. As of 2010-2014, the total Keystone population is 657, which has shrunk 4.37% since 2000. The population growth rate is much lower than the state average rate of 5.19% and is much lower than the national average rate of 11.61%. Keystone median household income is $56,354 in 2010-2014 and has grown by 54.57% since 2000. The income growth rate is much higher than the state average rate of 33.56% and is much higher than the national average rate of 27.36%. Keystone median house value is $93,400 in 2010-2014 and has grown by 35.17% since 2000. The house value growth rate is much lower than the state average rate of 53.09% and is lower than the national average rate of 46.91%. As a reference, the national Consumer Price Index (CPI) inflation rate for the same period is 26.63%. On average, the public school district that covers Keystone is much better than the state average in quality. The Keystone area code is 319.