Westfield is a city in Plymouth County, Iowa, United States. The population was 189 at the 2000 census. It is the westernmost point in Iowa, this being due to a bend in the Big Sioux River. A sign on the highway says "In Iowa, West Is The Best". The nearby Broken Kettle wildlife refuge is one of the few places in Iowa where rattlesnakes are commonly found. Westfield is the purported home town of the central character, Jack Smurch, in James Thurber's 1931 short story "The Greatest Man in the World. " Smurch flew a second-hand, single-motored monoplane in July 1937 all the way around the world, without stopping.